T(n,k)=Number of permutations of 0..floor((n*k-1)/2) on even squares of an nXk array such that each row, column, diagonal and (downwards) antidiagonal of even squares is increasing.
A215788
T(n,k)=Number of permutations of 0..floor((n*k-1)/2) on even squares of an nXk array such that each row, column, diagonal and (downwards) antidiagonal of even squares is increasing.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =1a(8) =1a(9) =1a(10) =1a(11) =1a(12) =1a(13) =1a(14) =1a(15) =1a(16) =2a(17) =2a(18) =1a(19) =1a(20) =1a(21) =1a(22) =2a(23) =5a(24) =2a(25) =1a(26) =1a(27) =1a(28) =1a(29) =5
External references
- oeis: A215788