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
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
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..80); # Alois P. Heinz, Aug 04 2008
MATHEMATICA
CoefficientList[Series[1/(1 -Total[x^Range[10, 20]]), {x, 0, 80}], 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}, 81] (* Harvey P. Dale, Oct 21 2016 *)
PROG
(Magma) R<x>:=PowerSeriesRing(Integers(), 80); 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))); // Vincenzo Librandi, Jul 01 2013
(SageMath)
def A017896_list(prec):
P.<x> = PowerSeriesRing(ZZ, prec)
return P( (1-x)/(1-x-x^10+x^21) ).list()
A017896_list(81) # G. C. Greubel, Nov 08 2024
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved