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 A159928 #13 Sep 08 2022 08:45:44 %S A159928 1,3,15,91,641,5147,46433,465081,5121789,61513799,800196799, %T A159928 11208394387,168193068805,2691956450679,45775335405729, %U A159928 824136306116113,15661462041469817,313277888390065739,6579708440058166031 %N A159928 a(n) is the sum of the terms of row n of triangle A159927. %C A159928 a(n) = -A075374(n+4) + A075374(n+3), for n >= 1; -A075374(n+4) = the sum of all terms of triangle A159927 in rows 1 through n. %o A159928 (Magma) S:=[1]; T:=S; s:=1; for m in [2..19] do T:=[ n lt m select T[n]+s else s: n in [1..m] ]; t:=&+T; s+:=t; Append(~S, t); end for; S; // _Klaus Brockhaus_, Jun 02 2009 %Y A159928 Cf. A159927, A075374. %K A159928 nonn %O A159928 1,2 %A A159928 _Leroy Quet_, Apr 26 2009 %E A159928 More terms from _Klaus Brockhaus_, Jun 02 2009