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A229125 Numbers of the form p * m^2, where p is prime and m > 0: union of A228056 and A000040. 9
2, 3, 5, 7, 8, 11, 12, 13, 17, 18, 19, 20, 23, 27, 28, 29, 31, 32, 37, 41, 43, 44, 45, 47, 48, 50, 52, 53, 59, 61, 63, 67, 68, 71, 72, 73, 75, 76, 79, 80, 83, 89, 92, 97, 98, 99, 101, 103, 107, 108, 109, 112, 113, 116, 117, 124, 125, 127, 128, 131, 137, 139, 147, 148, 149 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

No term is the product of two other terms.

Squares of terms and pairwise products of distinct terms form a subsequence of A028260.

Numbers n such that A162642(n)=1. - Jason Kimberley, Oct 10 2016

LINKS

Chris Boyd, Table of n, a(n) for n = 1..10000

MATHEMATICA

With[{nn=70}, Take[Union[Flatten[Table[p*m^2, {p, Prime[Range[nn]]}, {m, nn}]]], nn]] (* Harvey P. Dale, Dec 02 2014 *)

PROG

(PARI) test(n)=isprime(core(n))

for(n=1, 200, if(test(n), print1(n", ")))

CROSSREFS

Subsequence of A026424.

Cf. A028260, A162642, A229153.

Sequence in context: A026422 A026424 A298207 * A228853 A141832 A066680

Adjacent sequences:  A229122 A229123 A229124 * A229126 A229127 A229128

KEYWORD

nonn

AUTHOR

Chris Boyd, Sep 14 2013

STATUS

approved

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Last modified November 18 10:08 EST 2019. Contains 329261 sequences. (Running on oeis4.)