A125532 Number of n X n arrays with entries in 1..4 in which adjacent entries differ by 2 or less (adjacent means in x or y directions).

1, 4, 162, 75398, 386994338, 22039625597766, 13914188992963436802, 97391265572623379728784646, 7557580190940015054807296049439074, 6502004785230840000033839573162175747164038

Offset: 0

Author

R. H. Hardin, Dec 31 2006

Keywords

• nonn

Comments

[Empirical] a(base+1,n,diff)=a(base,n,diff)+F(n,diff) for base>=2.diff.(n-1) and F(n,diff)= (n=2, A063496(diff+1)) (n=3, A068744(diff+1)) (n=4, A068745(diff+1)) (n=5, A068746(diff+1)) (n=6, A068747(diff+1))