A125547 Number of n X n arrays with entries in 1..12 in which adjacent entries differ by 9 or less (adjacent means in x or y directions).

1, 12, 17782, 3359860178, 80173083905265254, 241867388512389264991124102, 92239510661284205765199147022065188442, 4446848187806762069273466271591426934850445380022534

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]`-$[i+1][j]`>9)+($[i+1][j]`-$[i][j]`>9)+($[j][i]`-$[j][i+1]`>9)+($[j][i+1]`-$[j][i]`>9)))

Crossrefs

Sequence in context: A301533 A013514 A340166 * A159421 A159369 A175882

Adjacent sequences: A125544 A125545 A125546 * A125548 A125549 A125550

Keyword

nonn

Author

R. H. Hardin, Dec 31 2006

Status

approved