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 A373657 #8 Jun 16 2024 04:46:47 %S A373657 1,-1,1,1,-1,-1,1,-1,-1,8,-8,1,1,1,7,-27,19,19,-27,7,1,-1,-21,54,54, %T A373657 -276,276,-54,-54,21,1,1,51,-25,-675,1650,-1002,-1002,1650,-675,-25, %U A373657 51,1,-1,-113,-372,3436,-5125,-5013,21216,-21216,5013,5125,-3436,372,113,1 %N A373657 Triangle read by rows: Coefficients of the polynomials P(n, x) * EP(n, x), where P denote the signed Pascal polynomials and EP the Eulerian polynomials A173018. %H A373657 S. Tanimoto, <a href="http://arXiv.org/abs/math.CO/0602263">A new approach to signed Eulerian numbers</a>, arXiv:math/0602263 [math.CO], 2006. (see p. 7) %e A373657 Triangle starts: %e A373657 [0] [ 1] %e A373657 [1] [-1, 1] %e A373657 [2] [ 1, -1, -1, 1] %e A373657 [3] [-1, -1, 8, -8, 1, 1] %e A373657 [4] [ 1, 7, -27, 19, 19, -27, 7, 1] %e A373657 [5] [-1, -21, 54, 54, -276, 276, -54, -54, 21, 1] %e A373657 [6] [ 1, 51, -25, -675, 1650, -1002, -1002, 1650, -675, -25, 51, 1] %p A373657 PolyProd := proc(P, Q, len) local ep, eq, epq, CL, n, k; %p A373657 ep := (n, x) -> simplify(add(Q(n, k)*x^k, k = 0..n)): %p A373657 eq := (n, x) -> simplify(add(P(n, k)*x^k, k = 0..n)): %p A373657 epq := (n, x) -> expand(ep(n, x) * eq(n, x)): %p A373657 CL := p -> PolynomialTools:-CoefficientList(p, x); %p A373657 seq(CL(epq(n, x)), n = 0..len); ListTools:-Flatten([%]) end: %p A373657 PolyProd((n, k) -> (-1)^(n-k)*binomial(n, k), combinat:-eulerian1, 7); %Y A373657 Cf. A173018, A049061, A101842, A000007 (row sums). %K A373657 sign,tabf %O A373657 0,10 %A A373657 _Peter Luschny_, Jun 15 2024