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

Author

Antti Karttunen, Dec 25 2017

Keywords

• nonn

Links

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

Crossrefs

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

Programs

PARI

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

Formula

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