3,3

Robert Israel, Table of n, a(n) for n = 3..10000

Marko Petkovsek and Helena Zakrajsek, Enumeration of I-graphs: Burnside does it again, Ars Mathematica Contemporanea, 2 (2009) 241-262.

A. Steimle and W. Staton, The isomorphism classes of the generalized Petersen graphs, Discrete Math. 309 (2009), 231-237.

a(n) = (A000010(n) + A060594(n) + A000089(n))/4.

# using functions A060594 and A000089 as defined in those sequences

f:= n -> (numtheory:-phi(n)+A060594(n)+A000089(n))/4:

map(f, [$3..100]); # Robert Israel, Sep 06 2018

Cf. A000010, A000089, A060594.

Sequence in context: A320385 A112222 A112220 * A241065 A086376 A160089

Adjacent sequences: A185275 A185276 A185277 * A185279 A185280 A185281

nonn,look

N. J. A. Sloane, Feb 19 2011

approved