- The transaction originally funding this brainwallet split 1 BTC into neat sets of 0.001 and 0.005 BTC. Could other outputs from this transaction - there are 101 in total - also be brainwallets, or some other kind of special address? Some are still unspent, 7.5 years later.
You can see that addresses are arranged alphabetically, sorted by first two letters (first is always lowercase).
Looks like addresses were generated by vanitygen.