4,2
CRC Handbook of Combinatorial Designs, 1996, p. 649.
Table of n, a(n) for n=4..13.
Sequence in context: A277055 A009258 A009204 * A025536 A162155 A163344
Adjacent sequences: A023639 A023640 A023641 * A023643 A023644 A023645
nonn
N. J. A. Sloane.
approved