

A166719


Numbers with at most 5 prime factors (counted with multiplicity)


2



1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 65, 66, 67, 68, 69, 70, 71, 72, 73
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OFFSET

1,2


COMMENTS

Complement of A046305, A001222(a(n))<=5


LINKS

G. C. Greubel, Table of n, a(n) for n = 1..10000


EXAMPLE

50 = 2*5*5 is in the sequence since it has 3 prime factors and 3 <= 5
64 = 2*2*2*2*2*2 is not in the sequence since it has 6 prime factors


MATHEMATICA

Select[Range[100], PrimeOmega[#]<6&] (* Harvey P. Dale, Jul 13 2011 *)


PROG

(PARI) isA166719(n) = (bigomega(n) <= 5)


CROSSREFS

Cf. A046305, A001222
For numbers with at most n prime factors: n=1: A000040, n=2: A037143, n=3: A037144, n=4: A166718.
Sequence in context: A146297 A296876 A144972 * A272159 A227981 A085736
Adjacent sequences: A166716 A166717 A166718 * A166720 A166721 A166722


KEYWORD

easy,nonn


AUTHOR

Michael B. Porter, Oct 20 2009


STATUS

approved



