Number of symmetric real invertible (0,1) n X n matrices with (-1,0,1) inverses.

A080636

Number of symmetric real invertible (0,1) n X n matrices with (-1,0,1) inverses.

Terms

    a(0) =1a(1) =4a(2) =28a(3) =334a(4) =7906a(5) =288676a(6) =18863944

External references