A294166 Row sums of A291843.

1, 0, 1, 8, 71, 789, 10365, 157031, 2692497, 51519756, 1088093185, 25140587651, 630820490833, 17082650998878, 496596665961713, 15425333714935513, 509890407550644949, 17871584701588777344, 662057571007292023593, 25847670560115633381442

Offset

0,4

Links

Gheorghe Coserea, Table of n, a(n) for n = 0..303

Formula

G.f. y(x) satisfies: 0 = 2*x^2*(1+x)*y*deriv(y,x) + x*y^2 - (1+x)^2*(1-2*x)*y + (1+x)*(1-2*x).

Prog

(PARI)
A291843_ser(N, t='t) = {
  my(x='x+O('x^N), y=1, y1=0, n=1,
  dn = 1/(-2*t^2*x^4 - (2*t^2+3*t)*x^3 - (2*t+1)*x^2 + (2*t-1)*x + 1));
  while (n++,
   y1 = (2*x^2*y'*((-t^2 + t)*x + (-t + 1) + (t^2*x^2 + (t^2 + t)*x + t)*y) +
        (t*x^2 + t*x)*y^2 - (2*t^2*x^3 + 3*t*x^2 + (-t + 1)*x - 1))*dn;
   if (y1 == y, break); y = y1; ); y;
};
Vec(A291843_ser(20, 1))

Crossrefs

Cf. A291843.

Sequence in context: A075506 A334670 A094911 * A203008 A235128 A226163

Adjacent sequences: A294163 A294164 A294165 * A294167 A294168 A294169

Keyword

nonn

Author

Gheorghe Coserea, Nov 05 2017

Status

approved