A051391 Number of nonisomorphic Steiner triple systems (STS's) S(2,3,v) on v = 6n+1 or 6n+3 points.

1, 1, 1, 1, 2, 80, 11084874829

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• nice
• hard

Examples

			There are 2 nonisomorphic STS's on 13 points.
		

References

• L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 304.
• CRC Handbook of Combinatorial Designs, 1996, p. 70.

Links

• Petteri Kaski and Patric R. J. Östergård, The Steiner triple systems of order 19
• Petteri Kaski and Patric R. J. Östergård, The Steiner triple systems of order 19, Mathematics of Computation, Vol. 73, No. 248 (Oct., 2004), pp. 2075-2092.
• Index entries for sequences related to Steiner systems

Crossrefs

Indexed by A047241. Cf. A001201, A030128, A030129, A051390, A124118, A124119.