A125543 Number of n X n arrays with entries in 1..10 in which adjacent entries differ by 7 or less (adjacent means in x or y directions).

1, 10, 8022, 543128374, 3055705944761702, 1431275227278696138328486, 55801019314977359729825524189282042, 181083160867536477536139285619272596798948123330

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]`-$[i+1][j]`>7)+($[i+1][j]`-$[i][j]`>7)+($[j][i]`-$[j][i+1]`>7)+($[j][i+1]`-$[j][i]`>7)))

Crossrefs

Sequence in context: A358920 A108089 A229152 * A291562 A203589 A109893

Adjacent sequences: A125540 A125541 A125542 * A125544 A125545 A125546

Keyword

nonn

Author

R. H. Hardin, Dec 31 2006

Status

approved