A320116 a(n) = Product_{d|n, d>1} prime(1+(d mod 6)).

1, 5, 7, 55, 13, 70, 3, 275, 49, 715, 13, 1540, 3, 75, 637, 3025, 13, 980, 3, 39325, 147, 715, 13, 15400, 39, 75, 343, 9075, 13, 140140, 3, 15125, 637, 715, 507, 43120, 3, 75, 147, 2162875, 13, 14700, 3, 39325, 31213, 715, 13, 338800, 9, 10725, 637, 9075, 13, 13720, 507, 226875, 147, 715, 13, 30830800, 3, 75, 7203, 166375, 507, 140140, 3

Offset: 1

Author

Antti Karttunen, Oct 06 2018

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..8192

Crossrefs

Cf. A320114, A320117 (rgs-transform),

Cf. also A319986.

Programs

PARI

A320116(n) = { my(m=1); fordiv(n,d,if(d>1, m *= prime(1+(d%6)))); (m); };

Formula

a(n) = Product_{d|n, d>1} prime(1+(d mod 6)).