A126415 Number of base 28 n-digit numbers with adjacent digits differing by two or less.

1, 28, 134, 650, 3168, 15486, 75848, 372024, 1826730, 8977530, 44151860, 217269760, 1069715430, 5268960200, 25962370558, 127969407686, 630947807506, 3111658441818, 15349331786976, 75731342285276, 373715745367376

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 28 differing by one or less A126382.

Sequence in context: A192796 A124956 A014705 * A187047 A201095 A239205

Adjacent sequences: A126412 A126413 A126414 * A126416 A126417 A126418

Keyword

nonn,base

Author

R. H. Hardin, Dec 28 2006

Status

approved