A126380 Number of base 26 n-digit numbers with adjacent digits differing by one or less.

1, 26, 76, 224, 662, 1960, 5810, 17238, 51180, 152040, 451874, 1343530, 3995984, 11888510, 35378800, 105307232, 313517862, 933569352, 2780376498, 8281841754, 24672375600, 73510750578, 219049521636, 652802078652, 1945651872306

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..24.

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: A262221 A139698 A124719 * A083578 A173307 A042326

Adjacent sequences: A126377 A126378 A126379 * A126381 A126382 A126383

Keyword

nonn,base

Author

R. H. Hardin, Dec 26 2006

Status

approved