Quote from: ranochigo on Today at 02:17:23 PM

It is simply just that the distribution of it is very skewed; addresses with lower case can only be 33 characters long due to the nature of base58 encoding[1].

Now that's something I never knew!

I've known for a long time that certain prefixes (for vanity addresses) take about 58 (or is it 60?) times longer to find, and I also noticed lower case is sometimes a cause. But not always, some capital characters are just as rare as their lower case equivalent in an address prefix, and a quick test shows that those too are indeed no more than 33 characters long.

Full test:

Code:

Difficulty: 256
Pattern: 11
Address: 114VsFm9DxGpdgQo47wskg1L8dZSskSRGP
Privkey: 5JFBfTyYpLAuBRKr7WMWykfXYVp4NFs9CD7EQvcp1y7oCW3HUPy

Difficulty: 23
Pattern: 12
Address: 12zqrBJdU5xRc5k3PzNPSYob26GFohzhJM
Privkey: 5JtzFH4MDCD1jxyWPXTZYfJAGoJepPKZM7eKYFtVdn9taYnhvP1

Difficulty: 23
Pattern: 13
Address: 13yAb2hzG9gs521w2M3FpGAfCU6WbVnWWT
Privkey: 5Jr8PvP8EUgSBvdokVJ5dPTXkhHHsRACL7uwyfh9P5LLqkNGYQs

Difficulty: 23
Pattern: 14
Address: 14rRFm6JfrMX6U7raCnwsbAopzyDuiKsrX
Privkey: 5KQmYGjmwXaiWRhQ3h9wTvTRYwDpQaWhpndXZww9Mko8BLspdGJ

Difficulty: 23
Pattern: 15
Address: 15prYdsR1HEoCGnqXgGUaDYP4nBXp7JC4G
Privkey: 5HpNn42gJhNhaXNWzStt8F9cKc3Ps7uuHbKg4AXGEVsYUZAEFHc

Difficulty: 23
Pattern: 16
Address: 16KEo2E6DvFxgRPwSSHeBETssJRjQykEHs
Privkey: 5J3dV6vu1JX6gScxjwvKhQbktfWcwfx189fqFp38W3smDKUbeTS

Difficulty: 22
Pattern: 17
Address: 17ZMxTjsc2Fd2o2XLDNz1jCzwfwMsJTkne
Privkey: 5K51h2Zba9z51okdXqkYmR7DbCN1EfP4E5pjDdoUpRVwuQJrt21

Difficulty: 22
Pattern: 18
Address: 18BC8jcptwJNSgi544cFbKfhvaPP7u2JeL
Privkey: 5JcBgAaiEMvxsuqPRFkn3EHxnoRkwfLWuRPVFVAn8WTAoANo6q9

Difficulty: 22
Pattern: 19
Address: 19oWg4ExcXJBNNE1teniqWy6Ksd4w6Zoaq
Privkey: 5Hrh9Tid3JfQ3oBw1XRKqAkrt7trkP872sYjWGqFKc1oi6VH2sJ

Difficulty: 22
Pattern: 1A
Address: 1AS741B31A4BPDv9CVgdgfBezLgUFti1oZ
Privkey: 5Ht543DD1QC5A3EDogr1tSJmHrgkR4ZFiuk4esZDBgtJqDKok7N

Difficulty: 22
Pattern: 1B
Address: 1B3hUNTmpTMkH87Ev2x3weDLp1c42HEaQv
Privkey: 5K5hbRwcGAYN3HfdNmveU1mG59qRH7AdD6jX8yqKTWSN2srjqtT
Difficulty: 22
Pattern: 1C
Address: 1CcDVv72KfFrsAeagT8e2RqHHTaGaGdEaG
Privkey: 5JJfquPxsYXjfZH3fwypy5qu7fRMmGSa6cK7GLEX6CSYYWYsCmZ

Difficulty: 22
Pattern: 1D
Address: 1DNo1oHYrDFCWBD4qc4gEQcwiAuy8yvarV
Privkey: 5Jhep42dq6V1rhJKyb1T6JQ4PSLDBQsooPpYVtfpWFgT67WZ3Nn

Difficulty: 22
Pattern: 1E
Address: 1EW2RZiArsSesZ3m8odMC1iZwQhq55Bwg
Privkey: 5HwQWx1GL19JykHVx8tWmCEMj5sY9ppBwhrbTrVhKN5yuKqvjoK

Difficulty: 22
Pattern: 1F
Address: 1FptoRgqe4Uuv9YeqDfw3TBugbBxpVRZdB
Privkey: 5KPNR2gAb7HHwuVaitix9Qg8sv6UhHNVMPpopMdr1q1ZFzknNJ1

Difficulty: 22
Pattern: 1G
Address: 1GQQyTkyGipGGMfq4KcTaZLg1UsR84GpTQ
Privkey: 5HtnUB1KMquCEptJAXjks9qLEsn5wxh3e22nKY4nA5BPCq8JUTk

Difficulty: 22
Pattern: 1H
Address: 1HEhdkS2vr86bWMURDXxckP9L82BCq1iym
Privkey: 5JfwyazuSnHmvKJPLewDwDaqZ1BuzeYz2dQurEBg7yQB99Dt3CW

Difficulty: 22
Pattern: 1J
Address: 1JPE2mPdqHBHJAMSzYrYMH2JkbUZHesXhv
Privkey: 5KSh8hkmdttEDxp7ATDuvaB9wje8ZgQgaPqcQhnPKDiJNvwi5Hj

Difficulty: 22
Pattern: 1K
Address: 1KEzKbLNqz9fL2DmxpcZnf4YhWQuP1GCuJ
Privkey: 5KQLwbsqXiVgzjABkfWC99Jnks16ZfNa4LymxjnP3bX2ubA7nv3

Difficulty: 22
Pattern: 1L
Address: 1LGwEkbVvPeqSb3i4DuUJAc4qvn3iLijjr
Privkey: 5JxSghXGLMno9ReAhhNDv3HnEM45S7CwnEm8RnLUFZuBp36aco6

Difficulty: 22
Pattern: 1M
Address: 1Mgj2qUaTd6jTrtCX6xUdTrVhd4fotnBxw
Privkey: 5HrBsDjUK1WN4NsXH4jaiaSbi3HbsXR2JxFf3shsaV1UmiPUr8p

Difficulty: 22
Pattern: 1N
Address: 1NSxnTao7UHrsGGU1LtmChTWj5DLodoVaF
Privkey: 5JJncGcgjBABDE29Br8qPKgrL6c5mKtxb83m28C2PcLtFZWoKFh

Difficulty: 22
Pattern: 1P
Address: 1PPtThiGdA6a6feVAL8jkmki5hRazkvnTv
Privkey: 5Ju1YWeQAng6qev14m9MQYMFbNALxEr9UyuSREB2cxZXaeaCBR5

Difficulty: 65
Pattern: 1Q
Address: 1QDKmij7XKtStb2BU3RXo6dn4RukEfrmbJ
Privkey: 5JEAE5A1fp7TS5W5xh9TWpMvtEL9jhdhadfATeSFY2Kpp5TFstV

Difficulty: 1353
Pattern: 1R
Address: 1RYxtUXxNHyYRi4vWGumKpFVB4vRmKf2P
Privkey: 5KVsXt15CNRRHfCxvZ7erpFzKh8tTxPS896H3TwcFqKzoYAG8xU

Difficulty: 1353
Pattern: 1S
Address: 1SaY5rx9H6cZnFk7RmxgdKjdvh7VXeVz6
Privkey: 5K6N1HCV6kgXLnuUWaeheSe6iQ6cBPviHYTpsxoNauypwewRF1k

Difficulty: 1353
Pattern: 1T
Address: 1TzV7Ldd5h9mjMomSiQAAEmiAHsDB2GrV
Privkey: 5K5zXbXVmVKnwZ1XduPXAZywTYdwNxsMsTBRY7DY8V4zgg49Qva

Difficulty: 1353
Pattern: 1U
Address: 1UyypjvQppm5cSXWdmhZFbPtzdZnrWpWr
Privkey: 5Hx2GTDg6eFsNbU9ioZ4X8LY4onpuFDLb5gc4eWLsDe7o3Du7pq

Difficulty: 1353
Pattern: 1V
Address: 1VeFGtZRUWkc7nzTXc8j31WUzhrsCzaQG
Privkey: 5K3x3JJmZzh6rkYiuKwyFhR6UgJpvPUGamXeFs9TJEdnFHhBKXu

Difficulty: 1353
Pattern: 1W
Address: 1WqZ3qYRPPMzADu4SXaZmDBNTxnaEw5SJ
Privkey: 5KE5UT2CJ6VTv3V8jgqhLk6LDEEtFxWbz9Zw7XPVuhsTXkmpwoC

Difficulty: 1353
Pattern: 1X
Address: 1XXRgH9u2G9RzetbcKtRDP7A6DksZdgVY
Privkey: 5JSmMxu6myNt4qpj6zZNYs8iQsEQso5QUwSrbpCnuLou7K2YbdT

Difficulty: 1353
Pattern: 1Y
Address: 1YkLunj67HoTexqArsqV7CWw6sC8VLWYT
Privkey: 5J7KLCNhjo5v1xXbLtAym3FRjg4yNnkXD9nwFCHdv391wHma1LM

Difficulty: 1353
Pattern: 1Z
Address: 1ZHCQeRftCDpzuZUqwC9B1BTsU686AF59
Privkey: 5K1wJdX2Gf1C99GoxrmibRV1LTiQsy6NxnoFcZGmAWbrTejEK9C

Difficulty: 1353
Pattern: 1a
Address: 1aLAdpf68i1dn2LimdVP9VAsrryCYM66v
Privkey: 5K9Q9Z7NKhYGADpk7DNK5mE9iUueKYLUMDgxnKRsPgtmyAnjjeo

Difficulty: 1353
Pattern: 1b
Address: 1bQNYGzXi6nr6KfzyRmRPByjwMhky6dEh
Privkey: 5K8rhip1nGMrs5n7C11y3E7pB8vQimE2Df7GnCYKXMKxBRnTjfT
Difficulty: 1353
Pattern: 1c
Address: 1cRURc5Fr1UyWBmAWLAu6HQJta83UqerH
Privkey: 5JMYdMDyAgkvrks3F9fHxASvu37TG9cbWYEKME2g3zUFnhQChaq

Difficulty: 1353
Pattern: 1d
Address: 1dJv8V1iBF5518dtwZGJNmp7oqaBxsdzC
Privkey: 5J1or4ZvuP7soN5jRof6G5JUhiE6fiQAKiA1tMerBHFgPcRn7n7

Difficulty: 1353
Pattern: 1e
Address: 1eQ3mfxFJEmESvuMnsScasn4nLX6mdXjH
Privkey: 5KhuGazfEmZgyeGksMPiiCaSd9EHimc5qDYfFv5fqSy4S8dGeXo

Difficulty: 1353
Pattern: 1f
Address: 1fnRCmk4Wr9BwxjfzndR2Die6DJYL4dAY
Privkey: 5K5ibfGw9Eom6m7bPR6bjTbQKbeGP3ixUEH5ebPoETpovv3AJAY

Difficulty: 1353
Pattern: 1g
Address: 1g1V8Y2EzGqwEGivmGpy85wEaseRjWjcN
Privkey: 5Hut5YnBKURJ5i96S84WwHirCxfZ3ZqL2ucJwvx8vzhMbtMd8Ky

Difficulty: 1353
Pattern: 1h
Address: 1hXkGKMFydYD4C29mrL9qgeCqfzJfT6q1
Privkey: 5Kkmgb2nr9HXsCMLizKafSHvygp1mR4HBHFfzZvWBwCm1X3tB3t

Difficulty: 1353
Pattern: 1i
Address: 1igNSXgjVtCXJ21wZxqsEtcFRCmYSMdD2
Privkey: 5JrK8VcmzdgVTyVgC3hkJ6ydyagBPeCzrzpAVAmKiMveQmYwtZp

Difficulty: 1353
Pattern: 1j
Address: 1jDrKvRYpfUDiuKYvBTiu5jg6HwFUrs6z
Privkey: 5J4QXkWQy1cP1LD4crciEjRTb7iqsFiqAqpeSAKxjrqw6TXo7Xn

Difficulty: 1353
Pattern: 1k
Address: 1kncsMGgx7SC2a8fuCRR6v46QQ8kim3vd
Privkey: 5JxbU2LTWX4T4pAtAvKmMzYW1fgU6AtXWnRuCEBWehiFM3Zffuv

Difficulty: 1353
Pattern: 1m
Address: 1mxQw4KfoeUjnrrSPiL4sX4NsVMMxjmjK
Privkey: 5K9HNojvGgkHktEkNp89BfT6EVQPiEkPfuNrfASTh3yAdPy19ro

Difficulty: 1353
Pattern: 1n
Address: 1ndRdkG27zWVzdWf22UfwCXoS5noVQFRQ
Privkey: 5HtLVdtQVdb5QFbVmFfeR6BP7JyRYVk12eqRoDJU2kJRprAmn5o

Difficulty: 1353
Pattern: 1o
Address: 1oazG4WTZQaEg1Jb49MW15mw6mHsT2Wgn
Privkey: 5KSGoTaD6fURR8yg6pYpjBTnWugkhPSvt2xnAFXGzHStmLtkoW6

Difficulty: 1353
Pattern: 1p
Address: 1p9w6JnuXmXKeqvHJyhDZU1AcrT6NNBdo
Privkey: 5Jb9xya8xHJsSKRsFGhU3jzeDWbUfsrcbXq8YLXQMt6PunFqMuT

Difficulty: 1353
Pattern: 1q
Address: 1qG8RGCjaPVGAxGNSxpFYmeoiwzapzTo4
Privkey: 5KSx3iSMQhJPvCrYJdtpHxfmw65zaBZeLvWJ5HMjX4tE6bdBE8g

Difficulty: 1353
Pattern: 1r
Address: 1rbpYWqAF2TTBVmXSzvEJGHGdQ1CnnMEu
Privkey: 5K9WBSnAxxdJMHo3wA6EBZq3xzHG16TVKGUKh7GZxPtPtL9VJws

Difficulty: 1353
Pattern: 1s
Address: 1sa5ty8VoEHVqLe8YvSarGtAUaYhwkp6E
Privkey: 5JmePMAQxU4mcga9wD4MrcUPcDftFAq7BJ472A1eyHaSn5e1vHG

Difficulty: 1353
Pattern: 1t
Address: 1t3VFGqmcWiDpMqANK1ZphpKX27cR1bn9
Privkey: 5J1tNfwri8eTkuLrYnswEAbLPefnmwmdtbUYmUbop7Gm5S1PVjk

Difficulty: 1353
Pattern: 1u
Address: 1u3n8juXMFXQNKxmYQ7oDT6LZuDe6yUtj
Privkey: 5Jawz2WZdGA8g3eU7V8E4J6B6VPN3GH9bS1MByVBzUe5Y3kJ4xr

Difficulty: 1353
Pattern: 1v
Address: 1vyVuGtvZsTDeuBd2SkkABnpfDPiBWdj7
Privkey: 5JKeRVuWz9k28qDfguybYAMRAbAtDdY5V8mV9zfu5VeFBhqqmAg

Difficulty: 1353
Pattern: 1w
Address: 1wWh4xi3z5kJr9qCbxWfWVHG7LDC8Fr3S
Privkey: 5JovfCGvJSxRFbp1fYQdoug1nw3bwYqGhZGJdSLf7fi6kTh1Jka

Difficulty: 1353
Pattern: 1x
Address: 1xnZ46vMKa1UvPnWVQLoBGs55eEuNEhaz
Privkey: 5Jw4ZSxYU6qXzwCgiUPPAmqExzLw31jp8kN7praK3GvGbZx9Ye3

Difficulty: 1353
Pattern: 1y
Address: 1yDeZP2YdZBrJt77bmKx43TzpBBCQzmdx
Privkey: 5Jnx4R8KwdKcHYDuu6hEoMicJEP2DjVBjjDfgBGqcGizVcy9iBv

Difficulty: 1353
Pattern: 1z
Address: 1zQ4iyEM2ftD2q4ggi2XKacxnDEvf18rP
Privkey: 5K9FTgjar3x8oV5qqe6yUCronVw36pVUSEdSyakhJnXfnCXy7Zm

The difficulty goes up at Q.