Number of n X n arrays of squares of integers, symmetric under 90 degree rotation, with all rows summing to 6.
A156442
Number of n X n arrays of squares of integers, symmetric under 90 degree rotation, with all rows summing to 6.
Terms
- a(0) =2a(1) =0a(2) =7a(3) =0a(4) =870a(5) =0a(6) =68180a(7) =0a(8) =18391220a(9) =0a(10) =10399874310a(11) =0a(13) =0a(15) =0
External references
- oeis: A156442