OFFSET
1,2
COMMENTS
Number of multiset partitions of integer partitions of 2^(n - 1) whose parts are constant and have equal sums.
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..120
EXAMPLE
The a(1) = 1 through a(4) = 16 partitions of partitions:
(1) (2) (4) (8)
(11) (22) (44)
(1)(1) (1111) (2222)
(2)(2) (4)(4)
(2)(11) (4)(22)
(11)(11) (22)(22)
(1)(1)(1)(1) (4)(1111)
(11111111)
(22)(1111)
(1111)(1111)
(2)(2)(2)(2)
(2)(2)(2)(11)
(2)(2)(11)(11)
(2)(11)(11)(11)
(11)(11)(11)(11)
(1)(1)(1)(1)(1)(1)(1)(1)
MATHEMATICA
Table[Sum[Binomial[k+2^(n-k)-1, k-1], {k, n}], {n, 20}]
PROG
(PARI) a(n) = sum(k=1, n, binomial(k+2^(n-k)-1, k-1)); \\ Michel Marcus, Jan 28 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Jan 27 2019
STATUS
approved