1,1

Table of n, a(n) for n=1..48.

a(2)=28 because 28=2*2*7 and 2^7 + 2^7 + 7^7 = 823799, a prime.

Cf. A006530.

Sequence in context: A141274 A224613 A134618 * A184838 A044073 A044454

Adjacent sequences: A108402 A108403 A108404 * A108406 A108407 A108408

nonn

Jason Earls, Jul 04 2005

More terms from Ryan Propper, Feb 11 2008

approved