1,3

Peter Kagey, Table of n, a(n) for n = 1..10000

If n = Product p(k)^e(k) then a(n) = Product [ (p(k)+1)/2 ]^e(k).

Multiplicative with a(p^e) = [(p+1)/2]^e. - David W. Wilson, Aug 01 2001

a(n) = 1 iff n is a power of 2 (A000079). - Michel Marcus, Nov 16 2017

(PARI) { A003960(n) = my(f); f=factor(n/2^valuation(n, 2)); prod(i=1, matsize(f)[1], ((f[i, 1]+1)/2)^f[i, 2] ); } \\ Max Alekseyev, Jul 27 2017

Cf. A003970.

Sequence in context: A228731 A163507 A003963 * A243499 A124223 A295908

Adjacent sequences: A003957 A003958 A003959 * A003961 A003962 A003963

nonn,mult

Marc LeBrun

approved