Sum(((-1)^k*binomial(4*n,k)),k=n..2*n).
A070808
Sum(((-1)^k*binomial(4*n,k)),k=n..2*n).
Terms
- a(0) =1a(1) =2a(2) =42a(3) =407a(4) =6890a(5) =88502a(6) =1385727a(7) =19762290a(8) =303169770a(9) =4514031830a(10) =69135179542
External references
- oeis: A070808