A245370 - OEIS

%I #15 Jun 13 2015 00:55:04

%S 1,0,0,1,0,1,1,0,2,2,1,3,3,3,6,5,6,11,10,13,19,19,27,35,37,52,65,74,

%T 100,121,145,192,230,282,365,440,548,695,843,1058,1327,1621,2035,2535,

%U 3119,3910,4851,5997,7503,9297,11528,14389,17829,22150,27596,34208,42536,52928,65655,81660,101525,126020,156738,194776,241888

%N Number of compositions of n into parts 3, 5 and 9.

%H <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,1,0,1,0,0,0,1).

%F G.f.: 1/(1-x^3-x^5-x^9).

%F a(n) = a(n-3) + a(n-5) + a(n-9).

%e a(28)=100 The compositions of n into parts 3,5 and 9 are the permutations of (9955)(these are 4!/2!2!=6), (555553) (these are 6!/5!=6), (955333) (these are 6!/3!2!=60), (55333333) (these are 8!/6!2!=28).

%o (PARI) Vec( 1/(1-x^3-x^5-x^9) +O(x^66) ) \\ _Joerg Arndt_, Aug 24 2014

%Y Cf. A079957, A245367, A245369.

%K nonn,easy

%O 0,9

%A _David Neil McGrath_, Aug 24 2014