A318589 Heinz numbers of integer partitions whose sum of reciprocals squared is the reciprocal of an integer.

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

Offset

1,1

Comments

The Heinz number of an integer partition (y_1, ..., y_k) is prime(y_1) * ... * prime(y_k).

Links

Table of n, a(n) for n=1..59.

Mathematica

Select[Range[2, 1000], IntegerQ[1/Total[If[#==1, {}, Cases[FactorInteger[#], {p_, k_}:>k/PrimePi[p]^2]]]]&]

Crossrefs

Cf. A001222, A051908, A056239, A058360, A112798, A289506, A289507, A316854, A316855.

Cf. A318584, A318585, A318586, A318587, A318588.

Sequence in context: A301987 A353393 A316857 * A132630 A033946 A328232

Adjacent sequences: A318586 A318587 A318588 * A318590 A318591 A318592

Keyword

nonn

Author

Gus Wiseman, Aug 29 2018

Status

approved