A174147 a(n) = n-th sum{p-1|p is prime and divisor of n} plus n-th product{p-1|p is prime and divisor of n}.

0, 2, 4, 2, 8, 5, 12, 2, 4, 9, 20, 5, 24, 13, 14, 2, 32, 5, 36, 9, 20, 21, 44, 5, 8, 25, 4, 13, 56, 15, 60, 2, 32, 33, 34, 5, 72, 37, 38, 9, 80, 21, 84, 21, 14, 45, 92, 5, 12, 9, 50, 25, 104, 5, 54, 13, 56, 57, 116, 15, 120, 61, 20, 2, 64, 33, 132, 33, 68, 35, 140, 5, 144, 73, 14

Offset: 1

Author

Juri-Stepan Gerasimov, Mar 09 2010

Keywords

• nonn

Comments

for n=1 sum{p-1|p is prime and divisor of 1} is zero.

Crossrefs

Cf. A055631, A173557.

Formula

a(n)=A055631(n)+A173557(n).

Extensions

Formula index corrected, a 62 replaced by 64 - R. J. Mathar, Apr 25 2010.