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 A326485 #10 Jul 13 2019 00:49:41 %S A326485 1,-1,1,1,-4,2,1,3,-6,2,-1,2,3,-4,1,-1,-5,5,5,-5,1,17,-24,-60,40,30, %T A326485 -24,4,17,119,-84,-140,70,42,-28,4,-31,34,119,-56,-70,28,14,-8,1,-31, %U A326485 -279,153,357,-126,-126,42,18,-9,1,691,-620,-2790,1020,1785,-504,-420,120,45,-20,2 %N A326485 T(n, k) = 2^A050605(n) * n! * [x^k] [z^n] (4*exp(x*z))/(exp(z) + 1)^2, triangle read by rows, for 0 <= k <= n. %C A326485 These are the coefficients of the generalized Euler polynomials (case m=2) with a different normalization. See A326480 for further comments. %e A326485 Triangle starts: %e A326485 [0] [ 1] %e A326485 [1] [ -1, 1] %e A326485 [2] [ 1, -4, 2] %e A326485 [3] [ 1, 3, -6, 2] %e A326485 [4] [ -1, 2, 3, -4, 1] %e A326485 [5] [ -1, -5, 5, 5, -5, 1] %e A326485 [6] [ 17, -24, -60, 40, 30, -24, 4] %e A326485 [7] [ 17, 119, -84, -140, 70, 42, -28, 4] %e A326485 [8] [-31, 34, 119, -56, -70, 28, 14, -8, 1] %e A326485 [9] [-31, -279, 153, 357, -126, -126, 42, 18, -9, 1] %p A326485 E2n := proc(n) (4*exp(x*z))/(exp(z) + 1)^2; %p A326485 series(%, z, 48); 2^A050605(n)*n!*coeff(%, z, n) end: %p A326485 for n from 0 to 9 do PolynomialTools:-CoefficientList(E2n(n), x) od; %Y A326485 Cf. A326480, A050605. %K A326485 sign,tabl %O A326485 0,5 %A A326485 _Peter Luschny_, Jul 12 2019