There were 100 BTC lost in two duplicated coinbase transactions (i.e. two pairs of blocks with the same coinbase txn, and as the protocol assumes txnID and output index are sufficient to designate an unspent output, means the later coinbase "overwrote" the earlier as it hadn't been spent by overwrite time), which is why version 2 blocks were created to eliminate that loophole.  So no, there are 150 BTC at first glance "granted" in blocks that are actually irretrievable forever.

There have been cases of miners claiming less than the reward + fees, "just for the hell of it", though I believe those are fractional BTC.

Then there was the Karpeles gox fuckup where he sent coins to provably unspendable scripts, because testnet was too much effort.  That was around 2600 BTC IIRC.

So almost 3 thousand BTC simply don't exist any more, no matter what random numbers some lucky bastard generates.