OFFSET
0,2
COMMENTS
This is the m=3 member of the m-family b(m,n) given in a comment on A214884, where also the formula and the o.g.f. are found.
FORMULA
O.g.f.: A(3,x) = -x*(3+x)/((1-x)^2*(1+3*x+x^2)). See the comment above.
a(n) = ((-1)^n*Fibonacci(2*n + 4) - 4*n - 3)/5. - Ehren Metcalfe, Aug 21 2017
MATHEMATICA
Table[Sum[(-1)^k*Fibonacci[k]*Fibonacci[k + 3], {k, 0, n}], {n, 0, 27}] (* Michael De Vlieger, Aug 23 2017 *)
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Wolfdieter Lang, Jul 30 2012
STATUS
approved