1,1

Essentially the same as A135731, A055670, A028815 and A008864. [From R. J. Mathar, Mar 13 2010]

Table of n, a(n) for n=1..58.

a(1) = 4, for n >= 2, a(n) = A008864(n) = A000040(n) + 1.

Sequence in context: A090682 A011982 A282939 * A053639 A100090 A222732

Adjacent sequences: A175213 A175214 A175215 * A175217 A175218 A175219

nonn,easy

Jaroslav Krizek, Mar 06 2010

approved