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 A316855 Heinz numbers of integer partitions whose reciprocal sum is 1. 23
 2, 9, 125, 147, 195, 2401, 3185, 4225, 6475, 6591, 7581, 10101, 10527, 16401, 20445, 20535, 21045, 25365, 46155, 107653, 123823, 142805, 161051, 164255, 164983, 171941, 218855, 228085, 267883, 304175, 312785, 333925, 333935, 335405, 343735, 355355, 390963 (list; graph; refs; listen; history; text; internal format)
 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). LINKS 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 Cf. A000041, A051908, A056239, A058360, A072411, A296150, A316854, A316856, A316857. Sequence in context: A237999 A194017 A135543 * A088862 A062457 A307539 Adjacent sequences:  A316852 A316853 A316854 * A316856 A316857 A316858 KEYWORD nonn AUTHOR Gus Wiseman, Jul 14 2018 STATUS approved

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Last modified February 19 01:00 EST 2020. Contains 332028 sequences. (Running on oeis4.)