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 A277598 #4 Dec 03 2016 11:51:37
%S A277598 2,7,12,17,20,22,27,32,37,42,47,52,57,62,67,70,72,77,82,87,92,97,102,
%T A277598 107,112,117,120,122,127,132,137,142,147,152,157,162,167,170,172,177,
%U A277598 182,187,192,197,200,202,207,212,217,220,222,227,232,237,242,247
%N A277598 (1/2)*A277591.
%H A277598 Clark Kimberling, <a href="/A277598/b277598.txt">Table of n, a(n) for n = 1..10000</a>
%t A277598 z = 260; a[b_] := Table[Mod[n/b^IntegerExponent[n, b], b], {n, 1, z}]
%t A277598 p[b_, d_] := Flatten[Position[a[b], d]]
%t A277598 p[10, 2]/2 (* A277597 *)
%t A277598 p[10,4]/3 (* A277598 *)
%t A277598 p[10,5]/5 (* A277599 *)
%t A277598 p[10,6]/2 (* A277600 *)
%t A277598 p[10,8]/2 (* A277601 *)
%Y A277598 Cf. A277591, A277597, A277599-A277601.
%K A277598 nonn,easy
%O A277598 1,1
%A A277598 _Clark Kimberling_, Nov 12 2016