A126382 Number of base 28 n-digit numbers with adjacent digits differing by one or less.

1, 28, 82, 242, 716, 2122, 6296, 18696, 55554, 165162, 491240, 1461628, 4350278, 12951392, 38567446, 114873170, 342215676, 1019662794, 3038656824, 9056682732, 26996898534, 80484319380, 239970228042, 715564197870

Offset

0,2

Comments

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

Links

Table of n, a(n) for n=0..23.

Prog

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

Crossrefs

Sequence in context: A043238 A044018 A124783 * A165009 A179790 A306427

Adjacent sequences: A126379 A126380 A126381 * A126383 A126384 A126385

Keyword

nonn,base

Author

R. H. Hardin, Dec 26 2006

Status

approved