The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation. Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A125530 Number of n X n arrays with entries in 1..3 in which adjacent entries differ by 1 or less (adjacent means in x or y directions). 0

%I

%S 1,3,35,2021,536453,661407975,3780952160847,100240477650720585,

%T 12324646884990466825513,7027467861520236770627093435,

%U 18582989792598188051914777397933755

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

%C [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))

%o (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]`>1)+(\$[i+1][j]`-\$[i][j]`>1)+(\$[j][i]`-\$[j][i+1]`>1)+(\$[j][i+1]`-\$[j][i]`>1)))

%K nonn

%O 0,2

%A _R. H. Hardin_, Dec 31 2006

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 1 04:06 EDT 2020. Contains 337441 sequences. (Running on oeis4.)