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A124806 Number of base 5 circular n-digit numbers with adjacent digits differing by 2 or less. 1
1, 5, 19, 65, 247, 955, 3733, 14649, 57583, 226505, 891219, 3507047, 13801285, 54313277, 213745019, 841177105, 3310392415, 13027820227, 51270096661, 201769982673, 794052091767, 3124938240153, 12297982928987, 48397879544975 (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..23.

FORMULA

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

G.f.: (1 - 3*x^2 - 10*x^3 + 3*x^4 + 4*x^5) / ((1 - x - x^2)*(1 - 4*x + x^3)).

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

(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: A001047 A099448 A239618 * A059509 A137745 A005021

Adjacent sequences:  A124803 A124804 A124805 * A124807 A124808 A124809

KEYWORD

nonn,base

AUTHOR

R. H. Hardin, Dec 28 2006

STATUS

approved

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Last modified May 29 08:07 EDT 2020. Contains 334697 sequences. (Running on oeis4.)