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A135685 Triangular sequence of the coefficients of the Numerator of the rational recursive sequence for Tan(n*y) with x=tan(y). 0
1, 0, 1, 0, -2, 0, -3, 0, 1, 0, 4, 0, -4, 0, 5, 0, -10, 0, 1, 0, -6, 0, 20, 0, -6, 0, -7, 0, 35, 0, -21, 0, 1, 0, 8, 0, -56, 0, 56, 0, -8, 0, 9, 0, -84, 0, 126, 0, -36, 0, 1, 0, -10, 0, 120, 0, -252, 0, 120, 0, -10, 0, -11, 0, 165, 0, -462, 0, 330, 0, -55, 0, 1 (list; graph; refs; listen; history; internal format)
OFFSET

1,5

FORMULA

p(x,0)=1;p(x,1)=x;p(x, n) = (p(x, n - 1) + x)/(1 - p(x, n - 1)*x);

EXAMPLE

{1},

{0, 1},

{0, -2},

{0, -3, 0,1},

{0, 4, 0, -4},

{0, 5, 0, -10, 0, 1},

{0, -6, 0, 20, 0, -6},

{0, -7, 0, 35, 0, -21, 0,1},

{0, 8, 0, -56, 0, 56, 0, -8},

{0, 9, 0, -84, 0, 126, 0, -36, 0, 1},

{0, -10, 0, 120, 0, -252, 0, 120,0, -10},

{0, -11, 0, 165, 0, -462, 0, 330, 0, -55, 0, 1}

MATHEMATICA

Clear[p, x, a, b] p[x, 0] = 1; p[x, 1] = x; p[x, 2] = 2*x/(1 - x^2); p[x, 3] = (3*x - x^3)/(1 - 3*x^2); p[x_, n_] := p[x, n] = (p[x, n - 1] + x)/(1 - p[x, n - 1]*x); c = Table[CoefficientList[Numerator[FullSimplify[p[x, n]]], x], {n, 0, 11}]; Flatten[c]

CROSSREFS

Sequence in context: A175663 A135523 A194663 * A164658 A079067 A160271

Adjacent sequences:  A135682 A135683 A135684 * A135686 A135687 A135688

KEYWORD

uned,sign

AUTHOR

Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Feb 17 2008

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Last modified February 15 20:26 EST 2012. Contains 205852 sequences.