0,4
F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 1973, p. 231.
P. K. Stockmeyer, The enumeration of graphs with prescribed automorphism group, Dissertation, Univ. of Michigan, Ann Arbor, 1971.
Table of n, a(n) for n=0..6.
Cf. A000273 (digraphs), A003400 (asymmetric graphs), A030242 (asymmetric relations)
Sequence in context: A243684 A260535 A220380 * A058881 A100520 A221342
Adjacent sequences: A051501 A051502 A051503 * A051505 A051506 A051507
hard,nonn,nice
Vladeta Jovovic
a(6) from Christian G. Bower Dec 15 1999.
approved
