A126495 Number of base 27 n-digit numbers with adjacent digits differing by three or less.

1, 27, 177, 1183, 7961, 53795, 364489, 2474351, 16821389, 114483903, 779844261, 5315901159, 36257137597, 247407046293, 1688869025869, 11532291728235, 78767464674013, 538108605910885, 3676788059570219, 25126354998525521

Offset

0,2

Comments

[Empirical] a(base,n)=a(base-1,n)+7^(n-1) for base>=3n-2; a(base,n)=a(base-1,n)+7^(n-1)-2 when base=3n-3

Links

Table of n, a(n) for n=0..19.

Prog

(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-2](($[i]`-$[i+1]`>3)+($[i+1]`-$[i]`>3))

Crossrefs

Cf. Base 27 differing by two or less A126414, one or less A126381.

Sequence in context: A248234 A083560 A125337 * A224454 A258637 A228463

Adjacent sequences: A126492 A126493 A126494 * A126496 A126497 A126498

Keyword

nonn,base

Author

R. H. Hardin, Dec 27 2006

Status

approved