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A318589 Heinz numbers of integer partitions whose sum of reciprocals squared is the reciprocal of an integer. 5
2, 3, 5, 7, 9, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 49, 53, 59, 61, 67, 71, 73, 79, 81, 83, 89, 97, 101, 103, 107, 109, 113, 125, 127, 131, 137, 139, 149, 151, 157, 163, 167, 169, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
The Heinz number of an integer partition (y_1, ..., y_k) is prime(y_1) * ... * prime(y_k).
LINKS
MATHEMATICA
Select[Range[2, 1000], IntegerQ[1/Total[If[#==1, {}, Cases[FactorInteger[#], {p_, k_}:>k/PrimePi[p]^2]]]]&]
CROSSREFS
Sequence in context: A301987 A353393 A316857 * A132630 A033946 A328232
KEYWORD
nonn
AUTHOR
Gus Wiseman, Aug 29 2018
STATUS
approved

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Last modified March 29 02:23 EDT 2024. Contains 371264 sequences. (Running on oeis4.)