OFFSET
0,3
LINKS
Index entries for linear recurrences with constant coefficients, signature (1, 0, 0, 1).
FORMULA
a(n) = a(n-1) + a(n-4); a(0)=0, a(1)=1, a(2)=2, a(3)=3
a(n+1)=sum{k=0..n, binomial(n-k, floor(k/3))} - Paul Barry, Jul 06 2004
G.f.: x(1+x+x^2)/(1-x-x^4). a(n)=A003269(n)+A003269(n-1)+A003269(n-2). [From R. J. Mathar, Nov 25 2008]
EXAMPLE
The sequence begins 0,1,2,3. a(5) = a(5-1) + a(5-4) = a(4)+a(1)= 3+0 =3. a(6) = a(6-1) + a(6-4) = a(5) + a(2) = 3+1 = 4.
MATHEMATICA
LinearRecurrence[{1, 0, 0, 1}, {0, 1, 2, 3}, 50] (* Harvey P. Dale, Oct 08 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Arran Fernandez, Jan 02 2003
STATUS
approved