A126381 Number of base 27 n-digit numbers with adjacent digits differing by one or less.

1, 27, 79, 233, 689, 2041, 6053, 17967, 53367, 158601, 471557, 1402579, 4173131, 12419951, 36973123, 110090201, 327866769, 976616073, 2909516661, 8669262243, 25834637067, 76997534979, 229509874839, 684183138261, 2039795051133

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: A255186 A121737 A124726 * A129254 A215782 A216438

Adjacent sequences: A126378 A126379 A126380 * A126382 A126383 A126384

Keyword

nonn,base

Author

R. H. Hardin, Dec 26 2006

Status

approved