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 A134277 #6 Sep 25 2024 09:42:56
%S A134277 1,4,41,519,9201,194819,4951381,144651394,4811109506,178860848394,
%T A134277 7364318416206,332403272058269,16329673772560231,867235540509998269,
%U A134277 49517829071816599856,3024950770151869836519,196866838411908745248981
%N A134277 Alternating row sums of triangle A134275 (S2(5)').
%F A134277 a(n) = Sum_{m=1..n} A134275(n,m)*(-1)^(m-1), n>=1.
%Y A134277 Cf. A134276 (row sums of triangle A134275).
%K A134277 nonn,easy
%O A134277 1,2
%A A134277 _Wolfdieter Lang_, Nov 13 2007