0,3

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

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

T. Tamura, Some contributions of computation to semigroups and groupoids, pp. 229-261 of J. Leech, editor, Computational Problems in Abstract Algebra. Pergamon, Oxford, 1970.

Eric Postpischil Posting to sci.math newsgroup, May 21 1990

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

Index entries for sequences related to groupoids

a(n) = (A001329(n) + A029850(n))/2

Cf. A001329, A029850.

Sequence in context: A145451 A144676 A125537 this_sequence A055318 A117661 A145253

Adjacent sequences: A001421 A001422 A001423 this_sequence A001425 A001426 A001427

nonn

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

Better description and corrected 4th term from Christian Bower (bowerc(AT)usa.net), Jan 15 1998. More terms, Jun 15 1998.