This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A192171 #7 Oct 21 2019 19:17:34
%S A192171 0,3,6,15,24,54,63,156,246,255,924,1014,1023,3096,3996,4086,4095,6384,
%T A192171 15384,16284,16374,16383,48576,55536,64536,65436,65526,65535,162144,
%U A192171 252144,261144,262044,262134,262143,948576,1038576,1047576,1048476,1048566,1048575
%N A192171 Monotonic ordering of nonnegative differences 4^i-10^j, for 40>=i>=0, j>=0.
%t A192171 c = 4; d = 10; t[i_, j_] := c^i - d^j;
%t A192171 u = Table[t[i, j], {i, 0, 40}, {j, 0, i*Log[d, c]}];
%t A192171 v = Union[Flatten[u ]]
%Y A192171 Cf. A192172.
%K A192171 nonn
%O A192171 1,2
%A A192171 _Clark Kimberling_, Jun 24 2011