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 A192118 #6 Oct 21 2019 19:25:28
%S A192118 0,1,3,7,9,15,25,31,57,63,79,121,127,169,207,249,255,463,505,511,681,
%T A192118 975,1017,1023,1695,1705,1999,2041,2047,3753,4047,4089,4095,5791,7849,
%U A192118 8143,8185,8191,13423,13983,15961,16041,16335,16377,16383,30367,32425,32719
%N A192118 Monotonic ordering of nonnegative differences 2^i-7^j, for 40>=i>=0, j>=0.
%t A192118 c = 2; d = 7; t[i_, j_] := c^i - d^j;
%t A192118 u = Table[t[i, j], {i, 0, 40}, {j, 0, i*Log[d, c]}];
%t A192118 v = Union[Flatten[u ]]
%Y A192118 Cf. A192119.
%K A192118 nonn
%O A192118 1,3
%A A192118 _Clark Kimberling_, Jun 23 2011