OFFSET
0,3
FORMULA
a(n) = Fibonacci(2*n+1)-Fibonacci(n+1). - Vladeta Jovovic, Jul 17 2004
G.f.: x*(1-x+x^2)/((1-3*x+x^2)*(1-x-x^2)). a(n)=F(2n+1)-F(n+1). - Mario Catalani (mario.catalani(AT)unito.it), Jul 19 2004
Binomial transform of A005013. - Michael Somos, Apr 13 2012
EXAMPLE
a(4)= F(4) + F(5) + F(6) + F(7) = 3 + 5 + 8 + 13 = 29.
x + 3*x^2 + 10*x^3 + 29*x^4 + 81*x^5 + 220*x^6 + 589*x^7 + ...
PROG
(PARI) a(n)=sum(k=n, 2*n-1, fibonacci(k))
(Maxima) makelist(fib(2*n+3)-fib(n+2), n, 0, 20); [Emanuele Munarini, Mar 29 2012]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Jul 16 2004
EXTENSIONS
Extended by Ray Chandler, Jul 17 2004
a(0)=0 by Michael Somos, Apr 13 2012
STATUS
approved