cp's OEIS Frontend

A177276 Triangle T(n,k) with the coefficient [x^k] of the polynomial (1+x^2)^n + 2*n*x*(1+x^2)^(n-1) in row n, column k, 0<=k<=2n.

%I A177276 #5 Jan 31 2013 18:50:04
%S A177276 1,1,2,1,1,4,2,4,1,1,6,3,12,3,6,1,1,8,4,24,6,24,4,8,1,1,10,5,40,10,60,
%T A177276 10,40,5,10,1,1,12,6,60,15,120,20,120,15,60,6,12,1,1,14,7,84,21,210,
%U A177276 35,280,35,210,21,84,7,14,1,1,16,8,112,28,336,56,560,70,560,56,336,28,112
%N A177276 Triangle T(n,k) with the coefficient [x^k] of the polynomial (1+x^2)^n + 2*n*x*(1+x^2)^(n-1) in row n, column k, 0<=k<=2n.
%C A177276 Row sums are 1, 4, 12, 32, 80, 192, 448, 1024, 2304, 5120, 11264,..., A001787.
%C A177276 This is a generalization of A162246 to polynomials (1+x^2)^n + q*n*x*(1+x^2)^(n-1), here q=2.
%e A177276 1;
%e A177276 1, 2, 1;
%e A177276 1, 4, 2, 4, 1;
%e A177276 1, 6, 3, 12, 3, 6, 1;
%e A177276 1, 8, 4, 24, 6, 24, 4, 8, 1;
%e A177276 1, 10, 5, 40, 10, 60, 10, 40, 5, 10, 1;
%e A177276 1, 12, 6, 60, 15, 120, 20, 120, 15, 60, 6, 12, 1;
%e A177276 1, 14, 7, 84, 21, 210, 35, 280, 35, 210, 21, 84, 7, 14, 1;
%e A177276 1, 16, 8, 112, 28, 336, 56, 560, 70, 560, 56, 336, 28, 112, 8, 16, 1;
%e A177276 1, 18, 9, 144, 36, 504, 84, 1008, 126, 1260, 126, 1008, 84, 504, 36, 144, 9, 18, 1;
%e A177276 1, 20, 10, 180, 45, 720, 120, 1680, 210, 2520, 252, 2520, 210, 1680, 120, 720, 45, 180, 10, 20, 1;
%t A177276 p[x_, n_] = (1 + x^2)^n + 2*n*x*(1 + x^2)^(n - 1);
%t A177276 Table[CoefficientList[p[x, n], x], {n, 0, 10}];
%t A177276 Flatten[%]
%Y A177276 Cf. A162246
%K A177276 nonn,tabf
%O A177276 0,3
%A A177276 _Roger L. Bagula_, May 06 2010