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A126395 Number of base 8 n-digit numbers with adjacent digits differing by two or less. 3
1, 8, 34, 150, 668, 2986, 13362, 59816, 267802, 1199022, 5368412, 24036226, 107618586, 481846232, 2157395218, 9659418342, 43248619100, 193639305850, 866991400098, 3881825980040, 17380302665002, 77817738944382 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

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

LINKS

Table of n, a(n) for n=0..21.

FORMULA

Conjectures from Colin Barker, Jun 01 2017: (Start)

G.f.: (1 + 3*x - 5*x^2 - 6*x^3) / (1 - 5*x + x^2 + 6*x^3).

a(n) = 5*a(n-1) - a(n-2) - 6*a(n-3) for n>3.

(End)

PROG

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

CROSSREFS

Cf. Base 8 differing by one or less A126362.

Sequence in context: A082840 A224240 A101644 * A335749 A227330 A252934

Adjacent sequences:  A126392 A126393 A126394 * A126396 A126397 A126398

KEYWORD

nonn,base

AUTHOR

R. H. Hardin, Dec 28 2006

STATUS

approved

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Last modified August 7 21:08 EDT 2022. Contains 355994 sequences. (Running on oeis4.)