A125544 Number of n X n arrays with entries in 1..10 in which adjacent entries differ by 8 or less (adjacent means in x or y directions).

1, 10, 9282, 809972882, 6620278776930050, 5070242688355834000238994, 363841631496359667433584638167920450, 2446405761143101128307819275435459905126486602002

Offset

0,2

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)).

Links

Table of n, a(n) for n=0..7.

Prog

(S/R) stvar $[N][N]:(0.. M-1) init $[][]:=0 asgn $[][]->{*} kill +[i in 0.. N-2](+[j in 0.. N-1](($[i][j]`-$[i+1][j]`>8)+($[i+1][j]`-$[i][j]`>8)+($[j][i]`-$[j][i+1]`>8)+($[j][i+1]`-$[j][i]`>8)))

Crossrefs

Sequence in context: A203589 A109893 A208781 * A137641 A137642 A163019

Adjacent sequences: A125541 A125542 A125543 * A125545 A125546 A125547

Keyword

nonn

Author

R. H. Hardin, Dec 31 2006

Status

approved