A125536 Number of n X n arrays with entries in 1..6 in which adjacent entries differ by 4 or less (adjacent means in x or y directions).

1, 6, 1058, 5748554, 948155870210, 4756811244059748042, 725704975038742796696062050, 3366853797682513115652233385161124618, 475014727091441236705100922925411926217680828034

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]`-$[i+1][j]`>4)+($[i+1][j]`-$[i][j]`>4)+($[j][i]`-$[j][i+1]`>4)+($[j][i+1]`-$[j][i]`>4)))

Crossrefs

Sequence in context: A370680 A004806 A282233 * A003763 A179853 A268043

Adjacent sequences: A125533 A125534 A125535 * A125537 A125538 A125539

Keyword

nonn

Author

R. H. Hardin, Dec 31 2006

Status

approved