1,2

a(n) is divisible by 3 for n > 7.

More generally, a(n) is divisible by m for all n >= 2^m. - Max Alekseyev, Aug 05 2015

Table of n, a(n) for n=1..10.

phi(33) = phi(34) = phi(35) = 4, so a(3)=4.

Cf. A006558.

Sequence in context: A166880 A079088 A161661 * A107634 A060659 A244363

Adjacent sequences: A115155 A115156 A115157 * A115159 A115160 A115161

nonn,more,hard

Jud McCranie, Jan 14 2006

a(10) from Jud McCranie, Nov 27 2018

approved