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A336068
Numbers k such that the exponent of the highest power of 3 dividing k (A007949) is a divisor of k.
3
3, 6, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 48, 51, 54, 57, 60, 66, 69, 72, 75, 78, 84, 87, 90, 93, 96, 102, 105, 108, 111, 114, 120, 123, 126, 129, 132, 135, 138, 141, 144, 147, 150, 156, 159, 165, 168, 174, 177, 180, 183, 186, 189, 192, 195, 198, 201, 204
OFFSET
1,1
COMMENTS
All the terms are divisible by 3 by definition.
Šalát (1994) proved that the asymptotic density of this sequence is 0.287106... (A336069).
LINKS
Tibor Šalát, On the function a_p, p^a_p(n) || n (n > 1), Mathematica Slovaca, Vol. 44, No. 2 (1994), pp. 143-151.
EXAMPLE
3 is a term since A007949(3) = 1 is a divisor of 3.
MATHEMATICA
Select[Range[200], Mod[#, 3] == 0 && Divisible[#, IntegerExponent[#, 3]] &]
PROG
(PARI) isok(m) = if (!(m%3), (m % valuation(m, 3)) == 0); \\ Michel Marcus, Jul 08 2020
CROSSREFS
A055777 is a subsequence.
Sequence in context: A067759 A331068 A310122 * A319451 A256882 A191267
KEYWORD
nonn
AUTHOR
Amiram Eldar, Jul 07 2020
STATUS
approved