1,1

When n is an odd prime a(n) = 3.

Antti Karttunen, Table of n, a(n) for n = 1..1001

a(n) = d(n) + 2 + (-1)^n. - Paul Boddington, Feb 02 2004

a(n) = A000005(n) + A176040(n). - Michel Marcus, Aug 19 2015

(PARI) a(n) = numdiv(n) + 2 + (-1)^n \\ Michel Marcus, Jul 30 2013

Cf. A062249, A007503, A062553.

Cf. A000005, A176040.

Sequence in context: A085825 A198140 A212614 * A226214 A160516 A264105

Adjacent sequences: A037849 A037850 A037851 * A037853 A037854 A037855

nonn

Ahmed Fares (ahmedfares(AT)my-deja.com), Jul 04 2001

More terms from Michel Marcus, Jul 30 2013

approved