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.

Different from A003802.

Sequence in context: A034606 A059044 A107617 this_sequence A003802 A033425 A153751

Adjacent sequences: A003806 A003807 A003808 this_sequence A003810 A003811 A003812

nonn,easy

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