OFFSET
1,3
COMMENTS
A rooted partition of n is an integer partition of n - 1.
EXAMPLE
The a(9) = 11 rooted twice-partitions:
(7), (61), (52), (43), (421),
(3)(3), (3)(21), (21)(3), (21)(21),
(1)(1)(1)(1),
()()()()()()()().
MATHEMATICA
Table[Sum[PartitionsQ[n/d-1]^d, {d, Divisors[n]}], {n, 50}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Mar 26 2018
STATUS
approved