A126366 Number of base 12 n-digit numbers with adjacent digits differing by one or less.

1, 12, 34, 98, 284, 826, 2408, 7032, 20562, 60186, 176312, 516844, 1515926, 4448336, 13058280, 38345702, 112633540, 330918226, 972433832, 2858069380, 8401323984, 24698783724, 72618671844, 213530132914, 627917268794

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.

Formula

Empirical G.f.: -(3*x^6+22*x^5-25*x^4-34*x^3+35*x^2-5*x-1) / (x^6+6*x^5-11*x^4-6*x^3+15*x^2-7*x+1). [Colin Barker, Nov 26 2012]

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: A139635 A124705 A296154 * A199114 A009760 A078194

Adjacent sequences: A126363 A126364 A126365 * A126367 A126368 A126369

Keyword

nonn,base

Author

R. H. Hardin, Dec 26 2006

Status

approved