cp's OEIS Frontend

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.

A118443 Row sums of triangle A118441, which is the matrix log of triangle A118435.

This page as a plain text file.
%I A118443 #14 Apr 08 2024 09:13:21
%S A118443 1,-2,3,-36,-155,474,1127,-1992,-1719,-4810,-31669,109332,286637,
%T A118443 -596974,-904785,449136,-3218287,16156782,50232979,-121747380,
%U A118443 -233735691,309853258,15768823,1624290984,6853579225,-19712646746,-44873974053,79998871428,90434035261
%N A118443 Row sums of triangle A118441, which is the matrix log of triangle A118435.
%H A118443 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (0,-12,0,-86,0,-300,0,-625).
%F A118443 G.f.: (1+x)*(1-3*x+18*x^2-78*x^3+45*x^4-175*x^5)/(1+6*x^2+25*x^4)^2.
%F A118443 E.g.f.: cos(2*x)*((1 - x)*cosh(x) + (1 + 3*x)*sinh(x)) - sin(2*x)*((1 + x)*cosh(x) - (1 - 3*x)*sinh(x)). - _Stefano Spezia_, Jul 01 2023
%t A118443 nmax = 30;
%t A118443 h[n_, k_] := Binomial[n, k]*(-1)^(Quotient[n+1, 2] - Quotient[k, 2]+n-k);
%t A118443 H = Table[h[n, k], {n, 0, nmax}, {k, 0, nmax}];
%t A118443 Cn = Table[Binomial[n, k], {n, 0, nmax}, {k, 0, nmax}];
%t A118443 L = MatrixLog[H.Inverse[Cn].H];
%t A118443 Total /@ Rest@L (* _Jean-François Alcover_, Apr 08 2024 *)
%o A118443 (PARI) {a(n)=polcoeff((1+x)*(1-3*x+18*x^2-78*x^3+45*x^4-175*x^5)/(1+6*x^2+25*x^4 +x*O(x^n))^2,n)}
%Y A118443 Cf. A118441 (triangle), A118442 (column 0), A118444 (a(n)/(n+1)); A118435.
%K A118443 sign,easy
%O A118443 0,2
%A A118443 _Paul D. Hanna_, Apr 28 2006