A118999 Number of real n X n symmetric (+1,-1) matrices with negative permanent.

1, 0, 32, 240, 11904, 533568, 134217728, 22741568512, 16885168208896

Offset: 1

Author

Giovanni Resta, May 08 2006

Keywords

• nonn
• more

Crossrefs

Cf. A118988, A118997, A118999, A118993, A118994, A118995, A119001, A119010.

Formula

a(n) = A118993(n) - A118995(n). For odd n, a(n) = A118995(n) = A118993(n)/2. - Max Alekseyev, Jun 18 2025

Extensions

a(1) corrected and a(8)-a(9) added by Max Alekseyev, Jun 18 2025