A126538 Number of base 17 n-digit numbers with adjacent digits differing by five or less.

1, 17, 157, 1507, 14607, 142041, 1382455, 13458785, 131037075, 1275829041, 12422061043, 120947162241, 1177600426155, 11465692698745, 111635587544291, 1086938653558289, 10582966126771531, 103040932264504713

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..17.

Formula

G.f.: (1+6*x-24*x^2-54*x^3+42*x^4+72*x^5-16*x^6-24*x^7) / (1-11*x+6*x^2+64*x^3-18*x^4-76*x^5+8*x^6+24*x^7) (conjectured). - Colin Barker, Jul 18 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 17 differing by four or less A126512, three or less A126485, two or less A126404, one or less A126371.

Sequence in context: A176838 A176622 A125380 * A164746 A198859 A160295

Adjacent sequences: A126535 A126536 A126537 * A126539 A126540 A126541

Keyword

nonn,base

Author

R. H. Hardin, Dec 28 2006

Status

approved