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A287031 Column 1 of A286782. 1
3, 45, 637, 9567, 156123, 2781389, 54043365, 1141864959, 26137086451, 645573913005, 17138071687053, 487130581207775, 14771502665168715, 476244289169954253, 16274079501768450421, 587711952558035789055, 22370368544174736836835, 895269564785985107345453, 37585737112233443277746589 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

LINKS

Gheorghe Coserea, Table of n, a(n) for n = 2..211

FORMULA

a(n) = (2*n-1)*A286786(n-1).

PROG

(PARI)

A286781_ser(N, t='t) = {

  my(x='x+O('x^N), y0=1+O('x^N), y1=0, n=1);

  while(n++,

    y1 = (1 + x*y0 + 2*x^2*y0')*(1 - x*y0*(1-t))/(1-x*y0)^2;

    if (y1 == y0, break()); y0 = y1; );

  y0;

};

A286782_ser(N, t='t) = my(s=A286781_ser(N, t)); 1 + x*s + 2*x^2 * deriv(s, 'x);

Kol(K, N=20) = {

  my(v = A286782_ser(N+K+1, 't+O('t^(K+1))));

  vector(N, n, polcoeff(polcoeff(v, K+n), K));

};

Kol(1)

CROSSREFS

Cf. A286782.

Sequence in context: A141445 A076140 A131568 * A124487 A266698 A132303

Adjacent sequences:  A287028 A287029 A287030 * A287032 A287033 A287034

KEYWORD

nonn

AUTHOR

Gheorghe Coserea, May 18 2017

STATUS

approved

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Last modified July 23 00:43 EDT 2019. Contains 325228 sequences. (Running on oeis4.)