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A124807 Number of base 6 circular n-digit numbers with adjacent digits differing by 2 or less. 1
1, 6, 24, 84, 332, 1336, 5478, 22658, 94196, 392664, 1639274, 6849002, 28627874, 119688094, 500456806, 2092720174, 8751273556, 36596513060, 153042707976, 640011807436, 2676483843602, 11192882945426, 46807955443900 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

[Empirical] a(base,n)=a(base-1,n)+A005191(n+1) for base>=2.int(n/2)+1.

LINKS

Table of n, a(n) for n=0..22.

FORMULA

Conjectures from Colin Barker, Jun 04 2017: (Start)

G.f.: (1 - 6*x^2 - 16*x^3 + 15*x^4 + 8*x^5 - 5*x^6) / ((1 - 4*x - x^2 + x^3)*(1 - 2*x - x^2 + x^3)).

a(n) = 6*a(n-1) - 6*a(n-2) - 8*a(n-3) + 5*a(n-4) + 2*a(n-5) - a(n-6) for n>6.

(End)

PROG

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

CROSSREFS

Sequence in context: A118043 A317408 A166060 * A271789 A121532 A025472

Adjacent sequences:  A124804 A124805 A124806 * A124808 A124809 A124810

KEYWORD

nonn,base

AUTHOR

R. H. Hardin, Dec 28 2006

STATUS

approved

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Last modified October 23 14:29 EDT 2019. Contains 328345 sequences. (Running on oeis4.)