OFFSET
0,3
COMMENTS
Number of partitions of n into parts 1, 2, 5 and 9. - Ilya Gutkovskiy, May 13 2017
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (1,1,-1,0,1,-1,-1,1,1,-1,-1,1,0,-1,1,1,-1).
FORMULA
a(0)=1, a(1)=1, a(2)=2, a(3)=2, a(4)=3, a(5)=4, a(6)=5, a(7)=6, a(8)=7, a(9)=9, a(10)=11, a(11)=13, a(12)=15, a(13)=17, a(14)=20, a(15)=23, a(16)=26, a(n)=a(n-1)+a(n-2)-a(n-3)+a(n-5)-a(n-6)-a(n-7)+a(n-8)+ a(n-9)-a(n-10)-a(n-11)+a(n-12)-a(n-14)+a(n-15)+a(n-16)-a(n-17) [From Harvey P. Dale, Mar 03 2012]
MATHEMATICA
CoefficientList[Series[1/((1-x)(1-x^2)(1-x^5)(1-x^9)), {x, 0, 60}], x] (* or *) LinearRecurrence[{1, 1, -1, 0, 1, -1, -1, 1, 1, -1, -1, 1, 0, -1, 1, 1, -1}, {1, 1, 2, 2, 3, 4, 5, 6, 7, 9, 11, 13, 15, 17, 20, 23, 26}, 60] (* Harvey P. Dale, Mar 03 2012 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved