A330954 Number of integer partitions of n whose product is divisible by the sum of primes of their parts.
0, 0, 0, 0, 0, 0, 1, 0, 2, 3, 4, 2, 3, 9, 8, 18, 15, 25, 35, 44, 50, 70, 71, 93, 141, 158, 226, 286, 337, 439, 532, 648, 789, 1013, 1261, 1454, 1776, 2176, 2701, 3258, 3823, 4606, 5521, 6613, 7810, 9202, 11074, 13145, 15498, 18413, 21818, 25774, 30481, 35718
Offset: 1
Keywords
Examples
The a(7) = 1 through a(15) = 8 partitions (empty column not shown): 43 63 541 83 552 6322 4433 5532 441 4222 3332 6411 7411 7322 6522 222211 5222 62221 44321 84111 33221 63311 333222 65111 432222 72221 3322221 433211 32222211 4322111 333111111 322211111 For example, the partition (3,3,2,2,1) has product 3 * 3 * 2 * 2 * 1 = 36 and sum of primes 5 + 5 + 3 + 3 + 2 = 18, and 36 is divisible by 18, so (3,3,2,2,1) is counted under a(11).
Crossrefs
The Heinz numbers of these partitions are given by A331378.
Partitions whose product is divisible by their sum are A057568.
Numbers divisible by the sum of their prime indices are A324851.
Partitions whose sum of primes divides their product of primes are A330953.
Partitions whose sum of primes divides of their product are A331381.
Partitions whose product equals their sum of primes are A331383.
Programs
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Mathematica
Table[Length[Select[IntegerPartitions[n],Divisible[Times@@#,Plus@@Prime/@#]&]],{n,30}]