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 A118437 #8 Oct 18 2024 08:23:02 %S A118437 1,2,0,8,-32,-128,320,128,2048,8192,-15360,2048,-131072,-524288, %T A118437 1064960,32768,8388608,33554432,-66846720,524288,-536870912, %U A118437 -2147483648,4299161600,8388608,34359738368,137438953472,-274810798080,134217728 %N A118437 Row sums of triangle A118435. %H A118437 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (2, -4, 8, -64, 128, -256, 512). %F A118437 G.f.: (1+8*x^3-32*x^5+384*x^6-256*x^7)/(1-2*x)/(1+4*x^2)/(1+64*x^4). %t A118437 nmax = 27; %t A118437 h[n_, k_] := Binomial[n, k]*(-1)^(Quotient[n+1, 2] - Quotient[k, 2]+n-k); %t A118437 H = Table[h[n, k], {n, 0, nmax}, {k, 0, nmax}]; %t A118437 Cn = Table[Binomial[n, k], {n, 0, nmax}, {k, 0, nmax}]; %t A118437 Total /@ (H.Inverse[Cn].H ) (* _Jean-François Alcover_, Apr 08 2024 *) %o A118437 (PARI) {a(n)=polcoeff((1+8*x^3-32*x^5+384*x^6-256*x^7)/(1-2*x)/(1+4*x^2)/(1+64*x^4+x*O(x^n)),n)} %Y A118437 Cf. A118435 (triangle), A118436 (column 0). %K A118437 sign %O A118437 0,2 %A A118437 _Paul D. Hanna_, Apr 28 2006