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 A137660 Triangular sequence of coefficients from the expansion of p(x,t)=Tan(x*t)/Tan(t). 0

%I

%S 0,1,0,-4,0,4,0,-64,0,-320,0,384,0,-7680,0,-26880,0,-161280,0,195840,

%T 0,-3096576,0,-10321920,0,-43352064,0,-263208960,0,319979520,0,

%U -3096576000,0,-10218700800,0,-40874803200,0,-173717913600,0,-1055932416000,0,1283840409600

%N Triangular sequence of coefficients from the expansion of p(x,t)=Tan(x*t)/Tan(t).

%C Row sums are: {1, 0, 0, 0, 0, 0, ...};

%F p(x,t)=Tan(x*t)/Tan(t)=Sum[P(x,n)*t^n/n!,{n,0,Infinity}]; out_n,m=(n+1)!*n!*Coefficients(p(x,n)) for even n.

%e {0, 1},

%e {0, -4, 0, 4},

%e {0, -64, 0, -320, 0, 384},

%e {0, -7680, 0, -26880, 0, -161280, 0, 195840},

%e {0, -3096576, 0, -10321920, 0, -43352064, 0, -263208960, 0, 319979520},

%e {0, -3096576000, 0, -10218700800, 0, -40874803200, 0, -173717913600, 0, -1055932416000, 0, 1283840409600}

%t p[t_] = Tan[x*t]/Tan[t]; Table[ ExpandAll[(n+1)!*n!*SeriesCoefficient[ Series[p[t], {t, 0, 30}], n]], {n, 0, 10,2}]; a = Table[ CoefficientList[(n+1)!*n!*SeriesCoefficient[ Series[p[t], {t, 0, 30}], n], x], {n, 0, 10}]; Flatten[a]

%K tabf,sign

%O 1,4

%A _Roger L. Bagula_, Apr 27 2008

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Last modified December 1 13:33 EST 2020. Contains 338843 sequences. (Running on oeis4.)