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A017860
Expansion of 1/(1-x^7-x^8-x^9-x^10-x^11).
1
1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 1, 2, 3, 4, 5, 4, 3, 3, 4, 6, 10, 15, 18, 19, 19, 19, 20, 26, 38, 53, 68, 81, 90, 95, 103, 122, 156, 205, 266, 330, 387, 437, 491, 566, 681, 852, 1079, 1344, 1625, 1911, 2211, 2562
OFFSET
0,16
COMMENTS
Number of compositions of n into parts p where 7 <= p <= 11. [Joerg Arndt, Jun 28 2013]
LINKS
FORMULA
a(n) = a(n-7) +a(n-8) +a(n-9) +a(n-10) +a(n-11) for n>10. - Vincenzo Librandi, Jun 28 2013
MATHEMATICA
CoefficientList[Series[1 / (1 - Total[x^Range[7, 11]]), {x, 0, 70}], x] (* Vincenzo Librandi, Jun 28 2013 *)
LinearRecurrence[{0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1}, {1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1}, 60] (* Harvey P. Dale, Jun 03 2023 *)
PROG
(Magma) m:=70; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/(1-x^7-x^8-x^9-x^10-x^11))); /* or */ I:=[1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1]; [n le 11 select I[n] else Self(n-7)+Self(n-8)+Self(n-9)+Self(n-10)+Self(n-11): n in [1..70]]; // Vincenzo Librandi, Jun 28 2013
CROSSREFS
Sequence in context: A271800 A073792 A017870 * A328765 A368822 A270434
KEYWORD
nonn,easy
AUTHOR
STATUS
approved