A011991 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A011991

(n,3,1) difference families over Z_n.

1, 0, 0, 0, 0, 0, 1, 0, 2, 0, 0, 0, 4, 0, 7, 0, 0, 0, 12, 0, 8, 0, 0, 0, 80, 0, 84, 0, 0, 0, 820, 0, 798, 0, 0, 0, 9508, 0, 11616, 0, 0, 0, 157340, 0, 139828, 0, 0, 0, 3027456, 0, 2353310

(list; graph; refs; listen; history; text; internal format)

OFFSET

7,9

REFERENCES

CRC Handbook of Combinatorial Designs, 1996, p. 285.

LINKS

Table of n, a(n) for n=7..57.

CROSSREFS

Sequence in context: A348613 A285182 A190608 * A234931 A129183 A374255

Adjacent sequences: A011988 A011989 A011990 * A011992 A011993 A011994

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved