OFFSET
0,2
LINKS
FORMULA
a(n) = Sum[ Trinomial[n, k] Pell[k], {k, 0, 2n} ] where Trinomial[n, k] = trinomial coefficients (A027907)
G.f.: (-2x+1)/(7x^2-10x+1).
MATHEMATICA
CoefficientList[Series[(-2x+1)/(7x^2-10x+1), {x, 0, 20}], x] (* or *) LinearRecurrence[{10, -7}, {1, 8}, 20] (* Harvey P. Dale, Sep 16 2018 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Emanuele Munarini, May 21 2003
STATUS
approved