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 A192199 #7 Oct 21 2019 15:09:24
%S A192199 0,4,16,24,44,116,124,544,616,624,2396,3044,3116,3124,9064,14896,
%T A192199 15544,15616,15624,19076,71564,77396,78044,78116,78124,331576,384064,
%U A192199 389896,390544,390616,390624,1421684,1894076,1946564,1952396,1953044,1953116,1953124
%N A192199 Monotonic ordering of nonnegative differences 5^i-9^j, for 40>= i>=0, j>=0.
%t A192199 c = 5; d = 9; t[i_, j_] := c^i - d^j;
%t A192199 u = Table[t[i, j], {i, 0, 40}, {j, 0, i*Log[d, c]}];
%t A192199 v = Union[Flatten[u ]]
%Y A192199 Cf. A192200.
%K A192199 nonn
%O A192199 1,2
%A A192199 _Clark Kimberling_, Jun 25 2011