login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A164409 Number of binary strings of length n with no substrings equal to 0000 0001 or 0100 1
13, 22, 39, 69, 121, 212, 372, 653, 1146, 2011, 3529, 6193, 10868, 19072, 33469, 58734, 103071, 180877, 317417, 557028, 977516, 1715421, 3010354, 5282803, 9270673, 16268897, 28549924, 50101624, 87922221, 154292742, 270764887, 475159253 (list; graph; refs; listen; history; text; internal format)
OFFSET

4,1

LINKS

R. H. Hardin, Table of n, a(n) for n=4..500

Index entries for linear recurrences with constant coefficients, signature (2,-1,1)

FORMULA

G.f.: x^4*(13-4*x+8*x^2)/(1-2*x+x^2-x^3). - R. J. Mathar, Nov 30 2011

MATHEMATICA

LinearRecurrence[{2, -1, 1}, {13, 22, 39}, 50] (* G. C. Greubel, Sep 19 2017 *)

PROG

(PARI) x='x+O('x^50); Vec(x^4*(13-4*x+8*x^2)/(1-2*x+x^2-x^3)) \\ G. C. Greubel, Sep 19 2017

CROSSREFS

Sequence in context: A164509 A164445 A164418 * A111676 A058030 A102498

Adjacent sequences:  A164406 A164407 A164408 * A164410 A164411 A164412

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 14 2009

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified November 17 19:53 EST 2017. Contains 294834 sequences.