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 A024855 #5 Oct 19 2021 11:45:03 %S A024855 1,0,0,1,2,3,4,1,2,3,4,5,7,9,11,4,5,6,8,10,12,14,16,18,20,9,11,13,15, %T A024855 17,19,21,23,26,29,32,35,18,20,22,24,26,29,32,35,38,41,44,47,50,53,29, %U A024855 32,35,38,41,44,47,50,53,56,59,62,66,70,74,78,47,50,53,56,59,62,65,68,72,76,80 %N A024855 a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (natural numbers), t = A023531. %Y A024855 Cf. A023531. %K A024855 nonn %O A024855 2,5 %A A024855 _Clark Kimberling_