Number of 2n X 4 0..3 arrays with values 0..3 introduced in row major order and each element equal to exactly two horizontal and vertical neighbors.
A198598
Number of 2n X 4 0..3 arrays with values 0..3 introduced in row major order and each element equal to exactly two horizontal and vertical neighbors.
Terms
- a(0) =1a(1) =5a(2) =32a(3) =251a(4) =1985a(5) =15761a(6) =125168a(7) =994127a(8) =7895777a(9) =62711837a(10) =498086240a(11) =3956031011a(12) =31420628321a(13) =249557171369
External references
- oeis: A198598