A099561 - OEIS

%I #5 Jun 13 2015 00:51:34

%S 0,0,0,0,1,1,1,1,3,4,5,6,10,14,19,25,36,50,69,94,131,181,250,344,476,

%T 657,907,1251,1728,2385,3292,4543,6272,8657,11949,16492,22765,31422,

%U 43371,59863,82629,114051,157422,217285,299915,413966,571388,788673

%N Sum C(n-3k,k-1), k=0..floor(n/4).

%H <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,0,2,-1,0,0,-1).

%F G.f.: x^4/((1-x^4)(1-x-x^4)); a(n)=a(n-1)+2a(n-4)-a(n-5)-a(n-8).

%Y Cf. A074331, A099560, A099562.

%K easy,nonn

%O 0,9

%A _Paul Barry_, Oct 22 2004