4,2

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

F. C. Holroyd and W. J. G. Wingate, Cycles in the complement of a tree or other graph, Discrete Math., 55 (1985), 267-282.

Sequence in context: A089950 A057835 A079755 this_sequence A164536 A037789 A037670

Adjacent sequences: A006181 A006182 A006183 this_sequence A006185 A006186 A006187

nonn

N. J. A. Sloane (njas(AT)research.att.com).