A370801 Expansion of (1/x) * Series_Reversion( x/(x+1/(1-x+x^4)) ).

1, 2, 5, 15, 50, 176, 638, 2351, 8735, 32523, 120707, 444218, 1611211, 5714056, 19578953, 63495983, 186784641, 442718804, 396470087, -4588483661, -45923198497, -305945783479, -1761810468901, -9395726622973, -47743575327196, -234512941253088, -1122653095777562

Offset

0,2

Links

Table of n, a(n) for n=0..26.

Index entries for reversions of series

Formula

a(n) = Sum_{k=0..n} binomial(n,k) * b(k), where g.f. B(x) = Sum_{k>=0} b(k)*x^k satisfies B(x) = (1/x) * Series_Reversion( x*(1-x+x^4) ).

Prog

(PARI) my(N=30, x='x+O('x^N)); Vec(serreverse(x/(x+1/(1-x+x^4)))/x)

Crossrefs

Cf. A370799, A370800.

Cf. A063028.

Sequence in context: A228343 A149949 A149950 * A024718 A149951 A367317

Adjacent sequences: A370798 A370799 A370800 * A370802 A370803 A370804

Keyword

sign

Author

Seiichi Manyama, Mar 02 2024

Status

approved