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 A192151 #6 Oct 21 2019 14:49:06
%S A192151 0,2,3,8,21,26,27,45,75,80,207,237,242,513,693,723,728,891,1971,2151,
%T A192151 2181,2186,5265,6345,6525,6555,6560,11907,12393,18387,19467,19647,
%U A192151 19677,19682,51273,57753,58833,59013,59043,59048,130491,169371,175851,176931
%N A192151 Monotonic ordering of nonnegative differences 3^i-6^j, for 40>= i>=0, j>=0.
%t A192151 c = 3; d = 6; t[i_, j_] := c^i - d^j;
%t A192151 u = Table[t[i, j], {i, 0, 40}, {j, 0, i*Log[d, c]}];
%t A192151 v = Union[Flatten[u ]]
%Y A192151 Cf. A192152.
%K A192151 nonn
%O A192151 1,2
%A A192151 _Clark Kimberling_, Jun 24 2011