|
| |
|
|
A102759
|
|
Number of partitions of n-set in which number of blocks of size 2k is even (or zero) for every k.
|
|
8
| |
|
|
1, 2, 8, 27, 82, 338, 1647, 7668, 37779, 210520, 1276662, 7985200, 51302500, 358798144, 2677814900, 20309850311, 160547934756, 1344197852830, 11666610870142, 104156661915427, 962681713955130, 9238216839975106
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
FORMULA
| E.g.f. for offset 2: exp(sinh(x))*Product_{k>=1} cosh(x^(2*k)/(2*k)!). - Geoffrey Critzer, Jan 02 2011
|
|
|
PROG
| (PARI) N=31; x='x+O('x^N);
Vec(serlaplace(exp(sinh(x))*prod(k=1, N, cosh(x^(2*k)/(2*k)!))))
/* gives: [1, 1, 1, 2, 8, 27, 82, 338, 1647, 7668, ...] , Joerg Arndt, Jan 03 2011 */
|
|
|
CROSSREFS
| Cf. A003483, A006950, A130219 - A130223.
Sequence in context: A184628 A092071 A100505 * A076884 A138388 A138386
Adjacent sequences: A102756 A102757 A102758 * A102760 A102761 A102762
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Vladeta Jovovic (vladeta(AT)eunet.rs), Feb 10 2005, Aug 05 2007
|
| |
|
|
