A125345 Number of base 8 circular n-digit numbers with adjacent digits differing by 4 or less.

1, 8, 52, 308, 2012, 13308, 88582, 590710, 3941716, 26308100, 175600282, 1172118538, 7823866514, 52224288462, 348597313326, 2326889050098, 15531999290132, 103676198275324, 692039319384424, 4619367120609720

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..19.

Formula

G.f.: (1 - 6*x^2 - 40*x^3 + 15*x^4 + 48*x^5 - 5*x^6 - 12*x^7) / ((1 - 2*x - x^2 + x^3)*(1 - 6*x - 5*x^2 + 3*x^3 + 2*x^4)) (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: A080279 A279283 A257285 * A111996 A016129 A006631

Adjacent sequences: A125342 A125343 A125344 * A125346 A125347 A125348

Keyword

nonn,base

Author

R. H. Hardin, Dec 28 2006

Status

approved