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A119251 Positive integers each with exactly 1 unitary prime divisor (i.e., n is included if and only if A056169(n) = 1). 0
2, 3, 5, 7, 11, 12, 13, 17, 18, 19, 20, 23, 24, 28, 29, 31, 37, 40, 41, 43, 44, 45, 47, 48, 50, 52, 53, 54, 56, 59, 61, 63, 67, 68, 71, 73, 75, 76, 79, 80, 83, 88, 89, 92, 96, 97, 98, 99, 101, 103, 104, 107, 109, 112, 113, 116, 117, 124, 127, 131, 135, 136, 137, 139, 147 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Also, numbers expressible as the product of a prime and a powerful number not divisible by that prime. - Franklin T. Adams-Watters, Jul 25 2006

LINKS

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

EXAMPLE

28 has the prime factorization of 2^2 * 7^1. 28 is therefore included in this sequence because there is exactly one prime raised to an exponent of 1 in 28's prime factorization.

MATHEMATICA

Select[Range@147, Count[FactorInteger@#, 1, 2] == 1 &] (* Robert G. Wilson v, Jul 25 2006 *)

CROSSREFS

Cf. A001694, A056169, Union of A000040 and A059404.

Sequence in context: A307714 A073085 A316793 * A182358 A212166 A293511

Adjacent sequences:  A119248 A119249 A119250 * A119252 A119253 A119254

KEYWORD

nonn

AUTHOR

Leroy Quet, Jul 23 2006

EXTENSIONS

More terms from Robert G. Wilson v and Franklin T. Adams-Watters, Jul 25 2006

STATUS

approved

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Last modified May 24 04:25 EDT 2019. Contains 323528 sequences. (Running on oeis4.)