A171464 a(n) = 0+1+2+...+n in dismal arithmetic in base 4 written in base 10.

0, 1, 2, 3, 7, 7, 7, 7, 11, 11, 11, 11, 15, 15, 15, 15, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 31, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 127, 127, 127, 127, 127, 127