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 A159926 #19 Jun 10 2025 11:56:52
%S A159926 1,4,16,77,447,3053,23978,212750,2103523,22926004,273008526,
%T A159926 3526184835,49093579165,732877502641,11676946463092,197775212369924,
%U A159926 3548276876195541,67219485435345356,1340841431830711580
%N A159926 The sum of all terms in row 1 through m of triangle A159924.
%C A159926 A159925 contains the row-sums of triangle A159924.
%H A159926 Michael De Vlieger, <a href="/A159926/b159926.txt">Table of n, a(n) for n = 1..449</a>
%F A159926 a(m) - a(m-1) = A159925(m), for m >= 2.
%p A159926 A159924 := proc(n,m) option remember ; local s; if n = m then 1; else s := add(add(procname(r,c),c=1..r),r=1..n-1) ; procname(n-1,m)+s ; fi; end: A159925 := proc(n) local m; add( A159924(n,m),m=1..n) ; end: A159926 := proc(n) add( A159925(k),k=1..n) ; end: seq(A159926(n),n=1..40) ; # _R. J. Mathar_, Apr 29 2009
%t A159926 Accumulate@ Map[Total, Block[{m = 0}, NestList[Block[{w = #}, AddTo[m, Total@ w]; Append[m + w, 1]] &, {1}, 18]]] (* _Michael De Vlieger_, Oct 30 2017 *)
%Y A159926 Cf. A159924, A159925.
%K A159926 nonn
%O A159926 1,2
%A A159926 _Leroy Quet_, Apr 26 2009
%E A159926 More terms from _R. J. Mathar_, Apr 29 2009