A125535 Number of n X n arrays with entries in 1..6 in which adjacent entries differ by 3 or less (adjacent means in x or y directions).

1, 6, 694, 1842302, 106627685414, 135334709216482502, 3763490062900640355493914, 2293235289704399729849626764238522, 30618002869205254395943653838381933205254046

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: A046985 A159371 A159620 * A364688 A343140 A116298

Adjacent sequences: A125532 A125533 A125534 * A125536 A125537 A125538

Keyword

nonn

Author

R. H. Hardin, Dec 31 2006

Status

approved