A126522 Number of base 27 n-digit numbers with adjacent digits differing by four or less.

1, 27, 223, 1887, 16103, 138099, 1188039, 10242351, 88435341, 764407997, 6612526647, 57234605067, 495599614141, 4292742043159, 37190688714579, 322257543592553, 2792687844075253, 24203507849388273, 209778422093025849

Offset

0,2

Comments

[Empirical] a(base,n)=a(base-1,n)+9^(n-1) for base>=4n-3; a(base,n)=a(base-1,n)+9^(n-1)-2 when base=4n-4

Links

Table of n, a(n) for n=0..18.

Prog

(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-2](($[i]`-$[i+1]`>4)+($[i+1]`-$[i]`>4))

Crossrefs

Cf. Base 27 differing by three or less A126495, two or less A126414, one or less A126381.

Sequence in context: A160441 A222994 A125364 * A273822 A027500 A069979

Adjacent sequences: A126519 A126520 A126521 * A126523 A126524 A126525

Keyword

nonn,base

Author

R. H. Hardin, Dec 28 2006

Status

approved