a(n) = (1/10)*(2^(4*n-1)-5^n*L(2*n)+L(4*n)), where L() = Lucas numbers A000032.
A133415
a(n) = (1/10)*(2^(4*n-1)-5^n*L(2*n)+L(4*n)), where L() = Lucas numbers A000032.
Terms
- a(0) =0a(1) =0a(2) =12a(3) =560a(4) =15504a(5) =346104a(6) =6906900a(7) =129024512a(8) =2310796740a(9) =40226003064a(10) =686392118544
External references
- oeis: A133415