2,1

J. H. Conway, R. T. Curtis, S. P. Norton, R. A. Parker and R. A. Wilson, ATLAS of Finite Groups. Oxford Univ. Press, 1985, p. xvi.

H. S. M. Coxeter and W. O. J. Moser, Generators and Relations for Discrete Groups, 4th ed., Springer-Verlag, NY, reprinted 1984, p. 131.

Sequence in context: A038821 A139780 A112446 this_sequence A003933 A092381 A084482

Adjacent sequences: A003937 A003938 A003939 this_sequence A003941 A003942 A003943

nonn,easy

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