login
A369058
a(n) = 1 if n is a product of three (not necessarily distinct) odd primes, otherwise 0.
5
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1
OFFSET
1
FORMULA
a(n) = A000035(n) * A101605(n).
EXAMPLE
a(27) = 1 because 27 = 3*3*3.
a(45) = 1 because 45 = 3*3*5.
PROG
(PARI) A369058(n) = ((n%2)&&(3==bigomega(n)));
CROSSREFS
Characteristic function of A046316.
Sequence in context: A011743 A011742 A011741 * A277165 A011740 A354344
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 20 2024
STATUS
approved