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A327829 Squarefree numbers with a prime number of prime factors. 0
6, 10, 14, 15, 21, 22, 26, 30, 33, 34, 35, 38, 39, 42, 46, 51, 55, 57, 58, 62, 65, 66, 69, 70, 74, 77, 78, 82, 85, 86, 87, 91, 93, 94, 95, 102, 105, 106, 110, 111, 114, 115, 118, 119, 122, 123, 129, 130, 133, 134, 138, 141, 142, 143, 145, 146, 154, 155, 158, 159, 161 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

210 is the first integer in A120944 but not here: it has 4 prime factors.

LINKS

Table of n, a(n) for n=1..61.

FORMULA

A006881 UNION A007304 UNION A046387 UNION A123321 UNION .... - R. J. Mathar, Oct 13 2019

MATHEMATICA

Select[Range@ 161, And[SquareFreeQ@ #, PrimeQ@ PrimeNu@ #] &] (* Michael De Vlieger, Sep 29 2019 *)

PROG

(PARI) isok(n) = issquarefree(n) && isprime(omega(n)); \\ Michel Marcus, Sep 27 2019

CROSSREFS

Subsequence of A120944.

A006881, A007304, A046387 are subsequences.

A046386, A067885 are not subsequences.

Sequence in context: A080365 A000469 A120944 * A052053 A276818 A325259

Adjacent sequences:  A327826 A327827 A327828 * A327830 A327831 A327832

KEYWORD

nonn

AUTHOR

Sebastian F. Orellana, Sep 26 2019

EXTENSIONS

Corrected and extended by Michel Marcus, Sep 27 2019

STATUS

approved

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Last modified February 29 05:01 EST 2020. Contains 332353 sequences. (Running on oeis4.)