A125320 Number of base 10 circular n-digit numbers with adjacent digits differing by 3 or less.

1, 10, 58, 286, 1618, 9330, 54994, 328058, 1973026, 11928418, 72360138, 439900746, 2677993234, 16317209282, 99477496666, 606677367546, 3700738695234, 22577766952946, 137756725752298, 840561549454570

Offset

0,2

Comments

[Empirical] a(base,n)=a(base-1,n)+A025012(n+1) for base>=3.int(n/2)+1

Links

Table of n, a(n) for n=0..19.

Formula

G.f.: (1 - 21*x^2 - 56*x^3 + 192*x^4 + 112*x^5 - 260*x^6 - 48*x^7 + 84*x^8) / ((1 + x)*(1 - 4*x + 2*x^3)*(1 - 7*x + 4*x^2 + 10*x^3 - 6*x^4)) (conjectured). - Colin Barker, Jun 01 2017

Prog

(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-1](($[i]`-$[(i+1)mod N]`>3)+($[(i+1)mod N]`-$[i]`>3))

Crossrefs

Sequence in context: A060157 A055583 A242202 * A321112 A126730 A126478

Adjacent sequences: A125317 A125318 A125319 * A125321 A125322 A125323

Keyword

nonn,base

Author

R. H. Hardin, Dec 28 2006

Status

approved