A048885 Number of nonisomorphic orthogonal arrays OA(4n,4n-1,2,2).

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

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• nice
• hard
• more

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

• Index entries for sequences related to Hadamard matrices

Crossrefs

Cf. A007299.

Extensions

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

a(8) from Brendan McKay, Feb 11 2012