Number of n X 3 0..2 arrays with top left element 0, horizontal differences mod 3 never 1, vertical differences mod 3 never -1, and antidiagonal differences never 0.
A229397
Number of n X 3 0..2 arrays with top left element 0, horizontal differences mod 3 never 1, vertical differences mod 3 never -1, and antidiagonal differences never 0.
Terms
- a(0) =4a(1) =13a(2) =44a(3) =153a(4) =536a(5) =1881a(6) =6604a(7) =23189a(8) =81428a(9) =285937a(10) =1004080a(11) =3525873a(12) =12381268a(13) =43477405a(14) =152672956a(15) =536118281a(16) =1882604616a(17) =6610854857a(18) =23214328476a(19) =81518208805a(20) =286255033124
External references
- oeis: A229397