Number of n X n 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, rows lexicographically nondecreasing, and columns lexicographically nonincreasing.
A229421
Number of n X n 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, rows lexicographically nondecreasing, and columns lexicographically nonincreasing.
Terms
- a(0) =3a(1) =12a(2) =83a(3) =754a(4) =7816a(5) =87648a(6) =1037193a(7) =12768612a(8) =162034856a(9) =2106287556a(10) =27919532994a(11) =376116911288
External references
- oeis: A229421