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A303822
Multiplicative with a(p^k) = 3^a(k).
2
1, 3, 3, 27, 3, 9, 3, 27, 27, 9, 3, 81, 3, 9, 9, 7625597484987, 3, 81, 3, 81, 9, 9, 3, 81, 27, 9, 27, 81, 3, 27, 3, 27, 9, 9, 9, 729, 3, 9, 9, 81, 3, 27, 3, 81, 81, 9, 3, 22876792454961, 27, 81, 9, 81, 3, 81, 9, 81, 9, 9, 3, 243, 3, 9, 81, 19683, 9, 27, 3, 81
OFFSET
1,2
COMMENTS
This sequence contains every power of 3; see A303823 for the corresponding least indices.
This sequence is a variant of A303809.
LINKS
FORMULA
a(n) = n iff n = A014222(k) for some k > 0.
a(A002110(k)) = 3^k for any k >= 0.
a(n) = 3 iff n is prime.
PROG
(PARI) a(n) = my (f=factor(n)); prod (i=1, #f~, 3^a(f[i, 2]))
CROSSREFS
KEYWORD
nonn,easy,mult
AUTHOR
Rémy Sigrist, May 01 2018
STATUS
approved