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 A137856 #9 Jun 24 2022 19:56:27
%S A137856 1,2,4,8,17,39,97,261,756,2343,7722,26917,98789,380360,1531698,
%T A137856 6434385,28130890,127729730,601196428,2928369917,14738842361,
%U A137856 76547694741,409718539681,2257459567236,12789959138943,74439150889080,444647798089245,2723583835351855
%N A137856 Row sums of triangle A137855.
%H A137856 Andrew Howroyd, <a href="/A137856/b137856.txt">Table of n, a(n) for n = 1..200</a>
%F A137856 a(n) = Sum_{k=1..n} Sum_{j=1..n-k+1} Stirling2(k, j). - _Andrew Howroyd_, Aug 09 2018
%e A137856 a(5) = 17 = sum of row 5 terms of triangle A137855: (1 + 2 + 5 + 8 + 1).
%o A137856 (PARI) a(n)={sum(k=1, n, sum(j=1, n-k+1, stirling(k,j,2)))} \\ _Andrew Howroyd_, Aug 09 2018
%Y A137856 Cf. A137855.
%Y A137856 Partial sums of A024427.
%K A137856 nonn
%O A137856 1,2
%A A137856 _Gary W. Adamson_, Feb 18 2008
%E A137856 Terms a(12) and beyond from _Andrew Howroyd_, Aug 09 2018