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 A192201 #7 Oct 21 2019 15:11:00
%S A192201 0,4,15,24,25,115,124,525,615,624,2125,3025,3115,3124,5625,14625,
%T A192201 15525,15615,15624,68125,77125,78025,78115,78124,290625,380625,389625,
%U A192201 390525,390615,390624,953125,1853125,1943125,1952125,1953025,1953115,1953124,8765625
%N A192201 Monotonic ordering of nonnegative differences 5^i-10^j, for 40>= i>=0, j>=0.
%t A192201 c = 5; d = 10; t[i_, j_] := c^i - d^j;
%t A192201 u = Table[t[i, j], {i, 0, 40}, {j, 0, i*Log[d, c]}];
%t A192201 v = Union[Flatten[u ]]
%Y A192201 Cf. A192202.
%K A192201 nonn
%O A192201 1,2
%A A192201 _Clark Kimberling_, Jun 25 2011