5,2

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

R. E. Peile, Some Topics in Combinatorial Theory. Ph. D. Dissertation, Oxford University, 1979.

Sequence in context: A018747 A110067 A145996 this_sequence A009673 A018770 A058990

Adjacent sequences: A005272 A005273 A005274 this_sequence A005276 A005277 A005278

nonn

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