A218033 G.f. A(x) satisfies A(x) = 1 + x * A(x) / A(x^2).

1, 1, 1, 0, -1, -2, -2, 0, 3, 6, 6, 2, -6, -14, -16, -8, 11, 32, 42, 26, -18, -74, -108, -82, 18, 162, 268, 238, 16, -344, -656, -664, -189, 694, 1570, 1792, 826, -1294, -3668, -4698, -2866, 2110, 8364, 12034, 8960, -2432, -18508, -30134, -26254, -910, 39492, 73862, 73560, 19120

Offset

0,6

Links

Alois P. Heinz, Table of n, a(n) for n = 0..1000 (terms up to n=200 from Vincenzo Librandi)

Mathematica

m = 60; A[_] = 1;
Do[A[x_] = 1 + x A[x]/A[x^2] + O[x]^m // Normal, {m}];
CoefficientList[A[x], x] (* Jean-François Alcover, Oct 04 2019 *)

Prog

(PARI)
N=66;  R=O('x^N);  x='x+R;
F = 1 + x;
for (k=1, N+1, F = 1 + x * F / subst(F, 'x, 'x^2) + R; );
Vec(F)

Crossrefs

Sequence in context: A061314 A366730 A193383 * A326500 A255903 A118262

Adjacent sequences: A218030 A218031 A218032 * A218034 A218035 A218036

Keyword

sign

Author

Joerg Arndt, Oct 19 2012

Status

approved