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 A086359 #5 Oct 15 2013 22:32:15
%S A086359 2,6,2,7,9,6,3,9,2,4,3,7,2,9,9,9,9,6,3,9,3,6,9,9,9,9,2,4,3,4,5,9,3,6,
%T A086359 9,7,5,6,2,7,9,9,9,9,9,9,9,9,9,9,9,9,9,6,3,9,3,6,9,9,9,9,3,6,9,6,3,9,
%U A086359 9,9,9,9,9,9,9,9,9,9,9,9,2,4,3,4,5,9,3,6,9,4,8,6,5,4,9,9,9,9,3,6,9,6,3,9,9
%N A086359 Fixed point if [decimal-digit-sum]-function at initial-value=A000984(n)=C[2n,n] is iterated.
%F A086359 a(n)=A010888[C[2n, n]]=fixed-point of A007953[C[2n, n]]; It equals C[2n, n] modulo(9); at r=0 use 9.
%e A086359 n=10, C[20,10]=184756, iteration list={184756,31,4},a(10)=4.
%t A086359 sud[x_] := Apply[Plus, DeleteCases[IntegerDigits[x], 0]] Table[FixedPoint[sud, Binomial[2*w, w]], {w, 1, 128}]
%Y A086359 Cf. A086353-A086361, A007953, A010888, A038194, A029898.
%K A086359 base,nonn
%O A086359 1,1
%A A086359 _Labos Elemer_, Jul 21 2003