login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A126476 Number of base 8 n-digit numbers with adjacent digits differing by three or less. 2
1, 8, 44, 252, 1446, 8300, 47642, 273466, 1569700, 9010108, 51718192, 296863410, 1704001644, 9781001986, 56143138234, 322262685896, 1849793972828, 10617852738356, 60946677537854, 349835093256180, 2008060117756986 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

[Empirical] a(base,n)=a(base-1,n)+7^(n-1) for base>=3n-2; a(base,n)=a(base-1,n)+7^(n-1)-2 when base=3n-3.

LINKS

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

FORMULA

Conjectures from Colin Barker, Jun 01 2017: (Start)

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

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

(End)

PROG

(S/R) stvar $[N]:(0..M-1) init $[]:=0 asgn $[]->{*} kill +[i in 0..N-2](($[i]`-$[i+1]`>3)+($[i+1]`-$[i]`>3))

CROSSREFS

Cf. Base 8 differing by two or less A126395, one or less A126362.

Sequence in context: A322498 A147828 A155604 * A220629 A210118 A112908

Adjacent sequences:  A126473 A126474 A126475 * A126477 A126478 A126479

KEYWORD

nonn,base

AUTHOR

R. H. Hardin, Dec 27 2006

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 27 19:04 EDT 2020. Contains 337388 sequences. (Running on oeis4.)