A297109 If n is prime(k)^e, e >= 1, then a(n) = k, otherwise 0.

0, 1, 2, 1, 3, 0, 4, 1, 2, 0, 5, 0, 6, 0, 0, 1, 7, 0, 8, 0, 0, 0, 9, 0, 3, 0, 2, 0, 10, 0, 11, 1, 0, 0, 0, 0, 12, 0, 0, 0, 13, 0, 14, 0, 0, 0, 15, 0, 4, 0, 0, 0, 16, 0, 0, 0, 0, 0, 17, 0, 18, 0, 0, 1, 0, 0, 19, 0, 0, 0, 20, 0, 21, 0, 0, 0, 0, 0, 22, 0, 2, 0, 23, 0, 0, 0, 0, 0, 24, 0, 0, 0, 0, 0, 0, 0, 25, 0, 0, 0, 26, 0, 27, 0, 0

Offset

1,3

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

Formula

If A001221(n) = 1 [when n is in A000961], then a(n) = A055396(n) = A001511(A297108(n)), otherwise 0.

Prog

(PARI) A297109(n) = if(1==omega(n), primepi(factor(n)[1, 1]), 0);

Crossrefs

Cf. A000720, A000961, A001221, A001511, A055396, A100995, A297108.

Sequence in context: A260437 A262677 A307742 * A073312 A350941 A166514

Adjacent sequences: A297106 A297107 A297108 * A297110 A297111 A297112

Keyword

nonn

Author

Antti Karttunen, Dec 25 2017

Status

approved