2,3
Computed using software at http://cs.anu.edu.au/~bdm/nauty/
Cf. A129422, A129432, A000421, A129417, A129419, A129423, A129425
Sequence in context: A133472 A087137 A056317 * A013227 A013223 A199224
Adjacent sequences: A129418 A129419 A129420 * A129422 A129423 A129424
nonn
Brendan McKay (bdm(at)cs.anu.edu.au), Apr 15 2007