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 A049726 #9 Aug 07 2021 01:13:11
%S A049726 1,4,18,31,73,105,204,249,412,501,760,865,1207,1376,1864,2070,2688,
%T A049726 2951,3740,4068,5059,5413,6612,7057,8421,8974,10620,11247,13114,13835,
%U A049726 16034,16812,19267,20221,22994,23973,27092,28240
%N A049726 a(n) = Sum_{i=0..floor(n/2)} T(2i,n-2i), array T as in A049723.
%K A049726 nonn
%O A049726 0,2
%A A049726 _Clark Kimberling_