A053555 Number of distinct parameter sets (v,k,lambda) for Abelian difference sets of order n = k-lambda with 1 <= lambda <= n-1.

1, 2, 3, 2, 1, 2, 1, 2, 5, 0, 2, 1, 1, 0, 1

Offset

2,2

Comments

a(17) is not known.

References

D. Jungnickel, Difference Sets, Chapter 7 of Jeffrey H. Dinitz and D. R. Stinson, Contemporary Design Theory, Wiley, 1992, see Appendix.

Links

Table of n, a(n) for n=2..16.

Example

The 3 parameter sets for order 4 are (v,k,lambda) = (21,5,1), (16,6,2) and (15,7,3).

Crossrefs

Sequence in context: A353486 A026490 A381031 * A324645 A124160 A265847

Adjacent sequences: A053552 A053553 A053554 * A053556 A053557 A053558

Keyword

nonn,nice,hard,more

Author

N. J. A. Sloane, Jan 17 2000

Status

approved