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A120446
Expansion of 1/(1-x-x^4-x^6).
1
1, 1, 1, 1, 2, 3, 5, 7, 10, 14, 21, 31, 46, 67, 98, 143, 210, 308, 452, 662, 970, 1421, 2083, 3053, 4475, 6558, 9611, 14085, 20643, 30254, 44340, 64983, 95237, 139576, 204559, 299796, 439373, 643932, 943728, 1383100, 2027032, 2970760, 4353861, 6380893
OFFSET
0,5
COMMENTS
Number of compositions of n into parts 1, 4, and 6. [Joerg Arndt, Sep 03 2013]
FORMULA
a(n) = a(n-1) + a(n-4) + a(n-6).
MATHEMATICA
CoefficientList[Series[1 / (1 - x - x^4 - x^6), {x, 0, 50}], x] (* Vincenzo Librandi, Sep 03 2013 *)
LinearRecurrence[{1, 0, 0, 1, 0, 1}, {1, 1, 1, 1, 2, 3}, 50] (* Harvey P. Dale, Feb 11 2020 *)
PROG
(Magma) I:=[1, 1, 1, 1, 2, 3]; [n le 6 select I[n] else Self(n-1)+Self(n-4)+Self(n-6): n in [1..50]]; // Vincenzo Librandi, Sep 03 2013
CROSSREFS
Sequence in context: A319564 A347869 A221943 * A082531 A291298 A092021
KEYWORD
easy,nonn
AUTHOR
Jon E. Schoenfield, Aug 27 2006
STATUS
approved