Hmm, apparently, the numbers 1 and 2 are replaced by the letters "M" and "L" and numbers 6 though 9 are skipped.
And the only ones that have only one button if I'm not mistaken are 11, 13, 14, 23, 24, 27, 30, 32, 36, 41, 42, 44, and 47, besides those two numberless buttons on the top right.
