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A325501
Product of Heinz numbers over all integer partitions of n.
5
1, 2, 12, 240, 120960, 638668800, 15064408719360000, 27259975545259032576000000, 682714624600511148826789083611136000000000, 2948964060660649503322235948384635104494106968064000000000000000
OFFSET
0,2
COMMENTS
Row-products of A215366 (positive integers arranged by sum of prime indices A056239).
The Heinz number of an integer partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k).
FORMULA
A001222(a(n)) = A006128(n).
A056239(a(n)) = A066186(n).
A003963(a(n)) = A007870(n).
A124010(a(n),i) = A066633(n,i).
EXAMPLE
The integer partitions of 3 are {(3), (2,1), (1,1,1)}, with Heinz numbers {5,6,8}, with product 240, so a(3) = 240.
The sequence of terms together with their prime indices begins:
1: {}
2: {1}
12: {1,1,2}
240: {1,1,1,1,2,3}
120960: {1,1,1,1,1,1,1,2,2,2,3,4}
638668800: {1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,3,3,4,5}
MATHEMATICA
Table[Times@@Prime/@(Join@@IntegerPartitions[n]), {n, 0, 5}]
KEYWORD
nonn
AUTHOR
Gus Wiseman, May 06 2019
STATUS
approved