Number of permutations of 0..floor((n*3-1)/2) on even squares of an n X 3 array such that each row and column of even squares is increasing.
A215287
Number of permutations of 0..floor((n*3-1)/2) on even squares of an n X 3 array such that each row and column of even squares is increasing.
Terms
- a(0) =1a(1) =3a(2) =10a(3) =30a(4) =140a(5) =420a(6) =2310a(7) =6930a(8) =42042a(9) =126126a(10) =816816a(11) =2450448a(12) =16628040a(13) =49884120a(14) =350574510a(15) =1051723530a(16) =7595781050a(17) =22787343150a(18) =168212023980a(19) =504636071940
External references
- oeis: A215287