A370804 - OEIS

A370804

Number of non-condensed integer partitions of n into parts > 1.

0, 0, 0, 0, 0, 0, 1, 0, 1, 2, 3, 3, 6, 6, 12, 14, 21, 25, 37, 43, 62, 75, 101, 124, 167, 198, 261, 316, 401, 488, 618, 745, 930, 1119, 1379, 1664, 2032, 2433, 2960, 3537, 4259, 5076, 6094, 7227, 8629, 10205, 12126, 14302, 16932, 19893, 23471, 27502, 32315, 37775

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OFFSET

0,10

COMMENTS

These are partitions without ones such that it is not possible to choose a different divisor of each part.

LINKS

Table of n, a(n) for n=0..53.

EXAMPLE

The a(6) = 1 through a(14) = 12 partitions:

(222) . (2222) (333) (3322) (3332) (3333) (4333) (4442)

(3222) (4222) (5222) (4422) (7222) (5333)

(22222) (32222) (6222) (33322) (5522)

(33222) (43222) (8222)

(42222) (52222) (33332)

(222222) (322222) (43322)

(44222)

(53222)

(62222)

(332222)

(422222)

(2222222)

MATHEMATICA

Table[Length[Select[IntegerPartitions[n], FreeQ[#, 1] && Length[Select[Tuples[Divisors/@#], UnsameQ@@#&]]==0&]], {n, 0, 30}]

CROSSREFS

These partitions have as ranks the odd terms of A355740.

The version with ones is A370320, complement A239312.

The complement without ones is A370805.

The version for prime factors is A370807, with ones A370593.

The version for factorizations is A370813, complement A370814.

A000005 counts divisors.

A000041 counts integer partitions, strict A000009.

A027746 lists prime factors, A112798 indices, length A001222.

A355731 counts choices of a divisor of each prime index, firsts A355732.

A355741, A355744, A355745 choose prime factors of prime indices.

Cf. A355529, A355739, A367867, A367901, A368110, A368413, A370595, A370806, A370808, A370810.

Sequence in context: A301703 A143715 A159685 * A251729 A187763 A187262

Adjacent sequences: A370801 A370802 A370803 * A370805 A370806 A370807

KEYWORD

nonn

AUTHOR

Gus Wiseman, Mar 03 2024

EXTENSIONS

More terms from Jinyuan Wang, Feb 14 2025

STATUS

approved