A126532 Number of base 11 n-digit numbers with adjacent digits differing by five or less.

1, 11, 91, 781, 6691, 57343, 491429, 4211559, 36093157, 309319197, 2650872719, 22718040927, 194694139719, 1668533310731, 14299369323775, 122545928057115, 1050221456858969, 9000422339067177, 77133829015319501

Offset

0,2

Comments

[Empirical] a(base,n)=a(base-1,n)+11^(n-1) for base>=5n-4; a(base,n)=a(base-1,n)+11^(n-1)-2 when base=5n-5.

Links

Table of n, a(n) for n=0..18.

Formula

G.f.: (1+3*x-3*x^2-4*x^3+x^4+x^5) / ((1+x)*(1-9*x+3*x^2+6*x^3-x^4-x^5)) (conjectured). - Colin Barker, Jul 17 2017

Prog

(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-2](($[i]`-$[i+1]`>5)+($[i+1]`-$[i]`>5))

Crossrefs

Cf. Base 11 differing by four or less A126506, three or less A126479, two or less A126398, one or less A126365.

Sequence in context: A005062 A125374 A245599 * A226868 A199678 A201549

Adjacent sequences: A126529 A126530 A126531 * A126533 A126534 A126535

Keyword

nonn,base

Author

R. H. Hardin, Dec 28 2006

Status

approved