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 A026658 #6 Mar 30 2012 18:56:09
%S A026658 1,1,2,4,6,11,17,30,47,86,133,242,375,679,1054,1914,2968,5389,8357,
%T A026658 15166,23523,42698,66221,120204,186425,338381,524806,952592,1477398,
%U A026658 2681683,4159081,7549278,11708359,21252226,32960585,59827870
%N A026658 Sum{T(n-k,k)}, 0<=k<=[ n/2 ], T given by A026648.
%F A026658 G.f.: (-x^6+2x^5+x^4+2x^3+x+1)/(x^8-4x^6-x^4-2x^2+1).
%K A026658 nonn
%O A026658 0,3
%A A026658 _Clark Kimberling_