OFFSET
0,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..303
Wikipedia, Partition of a set
FORMULA
a(n) = A290383(2*n+1).
EXAMPLE
a(0) = 1: 1.
a(1) = 2: 123, 1|23.
a(2) = 8: 12345, 123|45, 1245|3, 13|245, 145|23, 1|2345, 1|23|45, 1|245|3.
MAPLE
b:= proc(n, x, y) option remember; `if`(n=0, 1, `if`(n::even, 0,
b(n-1, y, x+1))+b(n-1, y, x)*x+b(n-1, y, x)*y)
end:
a:= n-> b(2*n+1, 0$2):
seq(a(n), n=0..20);
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Jun 10 2023
STATUS
approved