OFFSET
1,1
COMMENTS
The reciprocal sum of (y_1, ..., y_k) is 1/y_1 + ... + 1/y_k.
The Heinz number of an integer partition (y_1, ..., y_k) is prime(y_1) * ... * prime(y_k).
EXAMPLE
Sequence of all integer partitions whose reciprocal sum is 1 begins: (1), (2,2), (3,3,3), (4,4,2), (6,3,2), (4,4,4,4), (6,4,4,3), (6,6,3,3), (12,4,3,3), (6,6,6,2), (8,8,4,2).
MATHEMATICA
Select[Range[2, 10000], Sum[m[[2]]/PrimePi[m[[1]]], {m, FactorInteger[#]}]==1&]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Jul 14 2018
STATUS
approved