Number of n X n arrays of squares of integers, symmetric about main diagonal, with all rows summing to 4.

A156434

Number of n X n arrays of squares of integers, symmetric about main diagonal, with all rows summing to 4.

Terms

    a(0) =1a(1) =2a(2) =4a(3) =11a(4) =57a(5) =1082a(6) =42354a(7) =2278938a(8) =154294582a(9) =12767337844

External references