Number of n X n arrays of squares of integers, symmetric under 90 degree rotation, with all rows summing to 5.
A156439
Number of n X n arrays of squares of integers, symmetric under 90 degree rotation, with all rows summing to 5.
Terms
- a(0) =2a(1) =3a(2) =0a(3) =0a(4) =480a(5) =2400a(6) =0a(7) =0a(8) =7574400a(9) =66083040a(10) =0a(11) =0a(12) =896812758240a(14) =0a(15) =0a(18) =0a(19) =0
External references
- oeis: A156439