login
A126380
Number of base 26 n-digit numbers with adjacent digits differing by one or less.
4
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
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
KEYWORD
nonn,base
AUTHOR
R. H. Hardin, Dec 26 2006
STATUS
approved