login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A121833 Expansion of 1/(1-x^2-x^3-x^6). 2
1, 0, 1, 1, 1, 2, 3, 3, 6, 7, 10, 15, 20, 28, 41, 55, 79, 111, 154, 218, 306, 427, 603, 844, 1184, 1665, 2334, 3276, 4602, 6454, 9062, 12721, 17850, 25059, 35173, 49363, 69294, 97257, 136507, 191610, 268937, 377480, 529841, 743674, 1043828, 1465125 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,6
COMMENTS
Number of compositions of n into parts 2, 3, and 6. [Joerg Arndt, Sep 03 2013]
LINKS
S. Dominique Andres, On Multiperiodic Infinite Recursions and Their Finite Core, J. Int. Seq. 14 (2011) # 11.2.7
FORMULA
a(n) = a(n-2) + a(n-3) + a(n-6).
G.f.: -1 / ( (1+x)*(x^5-x^4+x^3+x-1) ). - R. J. Mathar, Aug 09 2017
MATHEMATICA
CoefficientList[Series[1 / (1 - x^2 - x^3 - x^6), {x, 0, 50}], x] (* Vincenzo Librandi, Sep 03 2013 *)
LinearRecurrence[{0, 1, 1, 0, 0, 1}, {1, 0, 1, 1, 1, 2}, 50] (* Harvey P. Dale, Dec 16 2016 *)
PROG
(Magma) I:=[1, 0, 1, 1, 1, 2]; [n le 6 select I[n] else Self(n-2)+Self(n-3)+Self(n-6): n in [1..50]]; // Vincenzo Librandi, Sep 03 2013
CROSSREFS
Sequence in context: A022474 A194189 A028249 * A091606 A027037 A276428
KEYWORD
easy,nonn,changed
AUTHOR
Jon E. Schoenfield, Aug 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 28 09:04 EDT 2024. Contains 371240 sequences. (Running on oeis4.)