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A231876 Numbers n such that omega(n)^2 (cf. A001221) divides n. 2
2, 3, 4, 5, 7, 8, 9, 11, 12, 13, 16, 17, 19, 20, 23, 24, 25, 27, 28, 29, 31, 32, 36, 37, 40, 41, 43, 44, 47, 48, 49, 52, 53, 56, 59, 61, 64, 67, 68, 71, 72, 73, 76, 79, 80, 81, 83, 88, 89, 90, 92, 96, 97, 100, 101, 103, 104, 107, 108, 109, 112, 113, 116, 121, 124, 125, 126, 127, 128, 131, 136, 137, 139, 144, 148, 149 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Includes all prime powers (A246655), as well as 4*A246655. - Robert Israel, Apr 25 2017

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..1100

MAPLE

select(n -> n mod nops(numtheory:-factorset(n))^2 = 0, [$2..1000]); # Robert Israel, Apr 25 2017

MATHEMATICA

Select[Range[2, 500], Mod[#, PrimeNu[#]^2] == 0  &] (* G. C. Greubel, Apr 24 2017 *)

PROG

(PARI) isok(n) = !(n % omega(n)^2); \\ Michel Marcus, Apr 25 2017

CROSSREFS

Cf. A001221, A075592, A185307, A001222, A074946, A134334, A231877 (complement).

Cf. A246655.

Sequence in context: A265640 A268375 A048683 * A304686 A085233 A133813

Adjacent sequences:  A231873 A231874 A231875 * A231877 A231878 A231879

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Nov 17 2013

STATUS

approved

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Last modified October 17 08:05 EDT 2019. Contains 328106 sequences. (Running on oeis4.)