A126413 Number of base 26 n-digit numbers with adjacent digits differing by two or less.

1, 26, 124, 600, 2918, 14236, 69598, 340774, 1670480, 8196280, 40245610, 197738510, 972059180, 4780678950, 23520964308, 115762376468, 569912653284, 2806482718416, 13823453975028, 68101963757630, 335568968553598

Offset

0,2

Comments

[Empirical] a(base,n)=a(base-1,n)+5^(n-1) for base>=2n-1; a(base,n)=a(base-1,n)+5^(n-1)-2 when base=2n-2

Links

Table of n, a(n) for n=0..20.

Prog

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

Crossrefs

Cf. Base 26 differing by one or less A126380.

Sequence in context: A296325 A183066 A124954 * A246032 A044358 A044739

Adjacent sequences: A126410 A126411 A126412 * A126414 A126415 A126416

Keyword

nonn,base

Author

R. H. Hardin, Dec 28 2006

Status

approved