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 A049618 #8 Aug 05 2021 19:49:10
%S A049618 0,0,2,3,9,11,22,26,43,49,74,82,115,126,168,184,239,256,322,343,421,
%T A049618 449,544,574,683,720,846,889,1035,1081,1244,1298,1479,1540,1746,1814,
%U A049618 2045,2120,2372,2456,2737,2826,3130,3229,3557,3669,4032,4146,4535,4661,5080
%N A049618 a(n) = Sum_{i=0..floor(n/2)} T(2i,n-2i) where T is A049615.
%K A049618 nonn
%O A049618 0,3
%A A049618 _Clark Kimberling_
%E A049618 More terms from _Sean A. Irvine_, Aug 05 2021