A125534 Number of n X n arrays with entries in 1..5 in which adjacent entries differ by 3 or less (adjacent means in x or y directions).

1, 5, 467, 877547, 32392165445, 23566800979324529, 337794127866926817026015, 95393532181581177183563991168527, 530759903230981312601669469700498881710153

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..8.

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]`-$[i+1][j]`>3)+($[i+1][j]`-$[i][j]`>3)+($[j][i]`-$[j][i+1]`>3)+($[j][i+1]`-$[j][i]`>3)))

Crossrefs

Sequence in context: A060855 A212043 A182403 * A320958 A262384 A024071

Adjacent sequences: A125531 A125532 A125533 * A125535 A125536 A125537

Keyword

nonn

Author

R. H. Hardin, Dec 31 2006

Status

approved