A302697 - OEIS

A302697

Odd numbers whose prime indices are relatively prime. Heinz numbers of integer partitions with no 1's and with relatively prime parts.

15, 33, 35, 45, 51, 55, 69, 75, 77, 85, 93, 95, 99, 105, 119, 123, 135, 141, 143, 145, 153, 155, 161, 165, 175, 177, 187, 195, 201, 205, 207, 209, 215, 217, 219, 221, 225, 231, 245, 249, 253, 255, 265, 275, 279, 285, 287, 291, 295, 297, 309, 315, 323, 327, 329

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OFFSET

1,1

COMMENTS

A prime index of n is a number m such that prime(m) divides n.

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..55.

EXAMPLE

Sequence of integer partitions with no 1's and with relatively prime parts begins:

015: (3,2)

033: (5,2)

035: (4,3)

045: (3,2,2)

051: (7,2)

055: (5,3)

069: (9,2)

075: (3,3,2)

077: (5,4)

085: (7,3)

093: (11,2)

095: (8,3)

099: (5,2,2)

105: (4,3,2)

119: (7,4)

123: (13,2)

135: (3,2,2,2)

MATHEMATICA

primeMS[n_]:=If[n===1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];

Select[Range[1, 200, 2], GCD@@primeMS[#]===1&]

CROSSREFS

Cf. A000837, A000961, A001222, A005117, A007359, A051424, A076078, A101268, A275024, A285572, A289509, A298748, A302568, A302569, A302696, A302698.

Sequence in context: A177204 A342193 A343338 * A337987 A154369 A243592

Adjacent sequences: A302694 A302695 A302696 * A302698 A302699 A302700

KEYWORD

nonn

AUTHOR

Gus Wiseman, Apr 11 2018

STATUS

approved