A057981 Number of singular n X n (-1,0,1)-matrices.

0, 1, 33, 7875, 15099201, 237634987683, 30805715676309201

Offset: 0

Author

Eric W. Weisstein, Oct 23 2000

Keywords

• nonn
• more

Links

• Eric Weisstein's World of Mathematics, Singular Matrix.
• Minfeng Wang, C++ program to calculate A057981

Crossrefs

Complement of A056989.

Cf. A060722, A330134.

Formula

a(n) = A060722(n) - A056989(n). - Alois P. Heinz, Dec 02 2019

Extensions

a(5) from Giovanni Resta, Feb 20 2009

a(0)=0 prepended by Alois P. Heinz, Dec 02 2019

a(0)-a(5) confirmed and a(6) added by Minfeng Wang, May 01 2024