A048885 - OEIS

A048885

Number of nonisomorphic orthogonal arrays OA(4n,4n-1,2,2).

1, 1, 1, 5, 3, 130, 7570, 355293682

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

OFFSET

1,4

COMMENTS

Equivalently, number of 3-(4*n,2*n,n-1) designs.

REFERENCES

A. S. Hedayat, N. J. A. Sloane and J. Stufken, Orthogonal Arrays, Springer-Verlag, NY, 1999, see Table 7.37 page 165.

LINKS

CROSSREFS

KEYWORD

nonn,nice,hard,more

AUTHOR

EXTENSIONS

a(7) computed by N. J. A. Sloane

a(8) from Brendan McKay, Feb 11 2012

STATUS

approved