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 A277597 #13 Nov 27 2016 16:01:42
%S A277597 1,6,10,11,16,21,26,31,36,41,46,51,56,60,61,66,71,76,81,86,91,96,100,
%T A277597 101,106,110,111,116,121,126,131,136,141,146,151,156,160,161,166,171,
%U A277597 176,181,186,191,196,201,206,210,211,216,221,226,231,236,241,246
%N A277597 a(n) = (1/2)*A277589(n).
%H A277597 Clark Kimberling, <a href="/A277597/b277597.txt">Table of n, a(n) for n = 1..10000</a>
%t A277597 z = 260; a[b_] := Table[Mod[n/b^IntegerExponent[n, b], b], {n, 1, z}]
%t A277597 p[b_, d_] := Flatten[Position[a[b], d]]
%t A277597 p[10, 2]/2 (* A277597 *)
%Y A277597 Cf. A277589.
%K A277597 nonn,easy
%O A277597 1,2
%A A277597 _Clark Kimberling_, Nov 12 2016