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 A261930 #9 Nov 18 2022 01:19:27 %S A261930 1,2,3,6,12,22,44,88,176,352,697,1394,2788,5576,11152,22304,44608, %T A261930 89172,178344,356688,713376,1426752,2853504,5707008,11414016,22828032, %U A261930 45655636,91311272,182622544,365245088,730490176,1460980352,2921960704,5843921408 %N A261930 Row sums of triangle A261897. %H A261930 Reinhard Zumkeller, <a href="/A261930/b261930.txt">Table of n, a(n) for n = 0..1000</a> %o A261930 (Haskell) %o A261930 a261930 = sum . a261897_row %Y A261930 Cf. A261897. %K A261930 nonn %O A261930 0,2 %A A261930 _Reinhard Zumkeller_, Sep 06 2015