a(0)=1; thereafter a(n) = -3*Sum_{k=1..n} binomial(2n,2k)*a(n-k).
A210676
a(0)=1; thereafter a(n) = -3*Sum_{k=1..n} binomial(2n,2k)*a(n-k).
Terms
- a(0) =1a(1) =-3a(2) =51a(3) =-2163a(4) =171231a(5) =-21785223a(6) =4065116811
External references
- oeis: A210676