A304711 - OEIS

A304711

Heinz numbers of integer partitions whose distinct parts are pairwise coprime.

2, 4, 6, 8, 10, 12, 14, 15, 16, 18, 20, 22, 24, 26, 28, 30, 32, 33, 34, 35, 36, 38, 40, 44, 45, 46, 48, 50, 51, 52, 54, 55, 56, 58, 60, 62, 64, 66, 68, 69, 70, 72, 74, 75, 76, 77, 80, 82, 85, 86, 88, 90, 92, 93, 94, 95, 96, 98, 99, 100, 102, 104, 106, 108, 110

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OFFSET

1,1

COMMENTS

Two parts are coprime if they have no common divisor greater than 1. For partitions of length 1 note that (1) is coprime but (x) is not coprime for x > 1.

First differs from A289509 at a(24) = 44, A289509(24) = 42.

LINKS

Table of n, a(n) for n=1..65.

EXAMPLE

Sequence of all partitions whose distinct parts are pairwise coprime begins (1), (11), (21), (111), (31), (211), (41), (32), (1111), (221), (311), (51), (2111), (61), (411), (321), (11111), (52), (71), (43), (2211), (81), (3111).

MATHEMATICA

Select[Range[200], CoprimeQ@@PrimePi/@FactorInteger[#][[All, 1]]&]

CROSSREFS

Cf. A000837, A007359, A018783, A051424, A056239, A078374, A101268, A289508, A289509, A298748, A300486, A302569, A302696, A302698, A302796, A302797, A304709.

Sequence in context: A280877 A289509 A336735 * A350803 A324847 A302696

Adjacent sequences: A304708 A304709 A304710 * A304712 A304713 A304714

KEYWORD

nonn

AUTHOR

Gus Wiseman, May 17 2018

STATUS

approved