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A017896
Expansion of 1/(1-x^10-x^11-x^12-x^13-x^14-x^15-x^16-x^17-x^18-x^19-x^20).
4
1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13, 15, 18, 22, 27, 33, 40, 48, 57, 68, 79, 92, 107, 125, 147, 174, 207, 247, 295, 353, 420, 499, 591, 698, 823, 970, 1144, 1351, 1598, 1894, 2246, 2666, 3165, 3756
OFFSET
0,21
COMMENTS
Number of compositions (ordered partitions) of n into parts 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 and 20. - Ilya Gutkovskiy, May 27 2017
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1).
FORMULA
a(n) = a(n-10) +a(n-11) +a(n-12) +a(n-13) +a(n-14) +a(n-15) +a(n-16) +a(n-17) +a(n-18) +a(n-19) +a(n-20), for n>19. - Vincenzo Librandi, Jul 01 2013
MAPLE
a:= n-> (Matrix(20, (i, j)-> if (i=j-1) or (j=1 and i in [$10..20]) then 1 else 0 fi)^n)[1, 1]: seq(a(n), n=0..70); # Alois P. Heinz, Aug 04 2008
MATHEMATICA
CoefficientList[Series[1 / (1 - Total[x^Range[10, 20]]), {x, 0, 70}], x] (* Vincenzo Librandi, Jul 01 2013 *)
LinearRecurrence[{0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, {1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, 70] (* Harvey P. Dale, Oct 21 2016 *)
PROG
(Magma) m:=70; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/(1-x^10-x^11-x^12-x^13-x^14-x^15-x^16-x^17-x^18-x^19-x^20))); /* or */ [n in [1] cat [11..20] select 1 else n in [2..10] select 0 else Self(n-10)+Self(n-11)+Self(n-12)+Self(n-13)+Self(n-14)+Self(n-15)+Self(n-16)+Self(n-17)+Self(n-18)+Self(n-19)+Self(n-20): n in [1..70]]; // Vincenzo Librandi, Jul 01 2013
CROSSREFS
Sequence in context: A254667 A011879 A011878 * A118868 A017885 A274165
KEYWORD
nonn,easy
AUTHOR
STATUS
approved