Number of n X 3 arrays of occupancy after each element moves to some horizontal, diagonal or antidiagonal neighbor, with no 2-loops and with no occupancy greater than 2.
A221397
Number of n X 3 arrays of occupancy after each element moves to some horizontal, diagonal or antidiagonal neighbor, with no 2-loops and with no occupancy greater than 2.
Terms
- a(0) =0a(1) =6a(2) =30a(3) =144a(4) =672a(5) =3108a(6) =14328a(7) =65976a(8) =303672a(9) =1397520a(10) =6431136a(11) =29594352a(12) =136184256a(13) =626677152a(14) =2883768672a(15) =13270180608a(16) =61065117312a(17) =281002082880
External references
- oeis: A221397