0,1

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

J. Berman, ``Free spectra of 3-element algebras,'' in R. S. Freese and O. C. Garcia, editors, Universal Algebra and Lattice Theory (Puebla, 1982), Lect. Notes Math. Vol. 1004, 1983.

Sequence in context: A081484 A125738 A092840 this_sequence A060346 A165946 A112357

Adjacent sequences: A007153 A007154 A007155 this_sequence A007157 A007158 A007159

nonn

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