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A278509 a(n) = 3^{number of primes congruent to 3 modulo 4 dividing n (with multiplicity)}. 3
1, 1, 3, 1, 1, 3, 3, 1, 9, 1, 3, 3, 1, 3, 3, 1, 1, 9, 3, 1, 9, 3, 3, 3, 1, 1, 27, 3, 1, 3, 3, 1, 9, 1, 3, 9, 1, 3, 3, 1, 1, 9, 3, 3, 9, 3, 3, 3, 9, 1, 3, 1, 1, 27, 3, 3, 9, 1, 3, 3, 1, 3, 27, 1, 1, 9, 3, 1, 9, 3, 3, 9, 1, 1, 3, 3, 9, 3, 3, 1, 81, 1, 3, 9, 1, 3, 3, 3, 1, 9, 3, 3, 9, 3, 3, 3, 1, 9, 27, 1, 1, 3, 3, 1, 9, 1, 3, 27, 1, 3, 3, 3, 1, 9, 3, 1, 9, 3, 3, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Fully multiplicative with a(p^e) = 1 if p = 2, (p mod 4)^e if p > 2.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A065338(A000265(n)) = A000265(A065338(n)).

a(n) = A000244(A065339(n)) = 3^A065339(n).

PROG

(Scheme) (define (A278509 n) (A065338 (A000265 n)))

CROSSREFS

Cf. A000244, A000265, A065338, A065339.

Cf. also A278265.

Sequence in context: A336456 A227898 A035649 * A094782 A035666 A060592

Adjacent sequences:  A278506 A278507 A278508 * A278510 A278511 A278512

KEYWORD

nonn,mult

AUTHOR

Antti Karttunen, Nov 28 2016

STATUS

approved

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Last modified April 14 06:59 EDT 2021. Contains 342946 sequences. (Running on oeis4.)