A121833 Expansion of 1/(1-x^2-x^3-x^6).

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

Offset

0,6

Comments

Number of compositions of n into parts 2, 3, and 6. [Joerg Arndt, Sep 03 2013]

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

S. Dominique Andres, On Multiperiodic Infinite Recursions and Their Finite Core, J. Int. Seq. 14 (2011) # 11.2.7

Index entries for linear recurrences with constant coefficients, signature (0,1,1,0,0,1).

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

Adjacent sequences: A121830 A121831 A121832 * A121834 A121835 A121836

Keyword

easy,nonn

Author

Jon E. Schoenfield, Aug 27 2006

Status

approved