A004040 Inversion of A000257.

1, 2, 6, 23, 103, 512, 2740, 15485, 91245, 555662, 3475090, 22214707, 144640291, 956560748, 6411521056, 43478151737, 297864793993, 2059159989914, 14350039389022, 100726680316559, 711630547589023, 5057282786190872, 36132861123763276, 259423620328055093, 1870954187618001253

Offset

0,2

Links

Table of n, a(n) for n=0..24.

Formula

Invert: define b by 1+Sum a(n)x^n = 1/(1 - Sum b(n)x^n).

Prog

(PARI) x='x+O('x^66); Vec( -1 + 32*x/(1+20*x-8*x^2-(1-8*x)^(3/2)) ) \\ Joerg Arndt, May 04 2013

Crossrefs

Cf. A000257.

Essentially the same as A022558.

Sequence in context: A301897 A374546 A022558 * A216040 A005802 A061552

Adjacent sequences: A004037 A004038 A004039 * A004041 A004042 A004043

Keyword

nonn

Author

N. J. A. Sloane

Extensions

More terms from Joerg Arndt, May 04 2013

Status

approved