A125344 Number of base 7 circular n-digit numbers with adjacent digits differing by 4 or less.

1, 7, 43, 247, 1527, 9497, 59245, 369803, 2308687, 14413783, 89990323, 561842893, 3507795765, 21900487967, 136732988323, 853675514807, 5329817595487, 33276057627697, 207754954396765, 1297092388823683, 8098236068810727

Offset

0,2

Comments

[Empirical] a(base,n)=a(base-1,n)+A025014(n+1) for base>=4.int(n/2)+1.

Links

Table of n, a(n) for n=0..20.

Formula

G.f.: (1 - 3*x^2 - 22*x^3 + 3*x^4 + 12*x^5) / ((1 - x - x^2)*(1 - 6*x - 2*x^2 + 3*x^3)) (conjectured). - Colin Barker, Jun 03 2017

Prog

(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-1](($[i]`-$[(i+1)mod N]`>4)+($[(i+1)mod N]`-$[i]`>4))

Crossrefs

Sequence in context: A081896 A363413 A193656 * A163869 A043553 A049609

Adjacent sequences: A125341 A125342 A125343 * A125345 A125346 A125347

Keyword

nonn,base

Author

R. H. Hardin, Dec 28 2006

Status

approved