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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).
0
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)).
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
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 31 2006
STATUS
approved