A032220 Number of ways to partition n labeled elements into pie slices of different odd sizes, allowing the pie to be turned over.

1, 1, 0, 1, 4, 1, 6, 1, 64, 505, 130, 1321, 1024, 13157, 2380, 395851, 17313664, 1639617, 73554666, 16100905, 919339264, 292018525, 18910614580, 1549052715, 1523900106304, 141366386526801, 9494469178116

Offset

0,5

Links

Andrew Howroyd, Table of n, a(n) for n = 0..200

C. G. Bower, Transforms (2)

Formula

"DGJ" (bracelet, element, labeled) transform of 1, 0, 1, 0... (odds).

Prog

(PARI) seq(n)=[subst(serlaplace(p/y + polcoeff(p, 1) + polcoeff(p, 2)), y, 1)/2 | p <- Vec(serlaplace(y-1+prod(k=1, ceil(n/2), 1 + x^(2*k-1)*y/(2*k-1)! + O(x*x^n))))] \\ Andrew Howroyd, Sep 11 2018

Crossrefs

Sequence in context: A087652 A072195 A032310 * A032145 A032050 A109915

Adjacent sequences: A032217 A032218 A032219 * A032221 A032222 A032223

Keyword

nonn

Author

Christian G. Bower

Extensions

a(0)=1 prepended by Andrew Howroyd, Sep 11 2018

Status

approved