a(n) = (1/2) * (number of n X n 0..4 matrices M with MM' mod 5 = I, where M' is the transpose of M and I is the n X n identity matrix).

A071304

a(n) = (1/2) * (number of n X n 0..4 matrices M with MM' mod 5 = I, where M' is the transpose of M and I is the n X n identity matrix).

Terms

    a(0) =1a(1) =4a(2) =120a(3) =14400a(4) =9360000a(5) =29016000000

External references