Number of n X n arrays of squares of integers, symmetric under 90 degree rotation, with all rows summing to 9.

A156450

Number of n X n arrays of squares of integers, symmetric under 90 degree rotation, with all rows summing to 9.

Terms

    a(0) =1a(1) =0a(2) =0a(3) =4a(4) =4a(5) =0a(6) =0a(7) =1836a(8) =6871a(9) =0a(10) =0a(11) =294400160a(12) =3360660500a(13) =0a(14) =0a(17) =0

External references