a(n) = Sum_{k=0..n} (-1)^(n-k) * binomial(n+2*k+1,k).
A390542
a(n) = Sum_{k=0..n} (-1)^(n-k) * binomial(n+2*k+1,k).
Terms
- a(0) =1a(1) =3a(2) =17a(3) =97a(4) =580a(5) =3549a(6) =22070a(7) =138839a(8) =881047a(9) =5629040a(10) =36160422a(11) =233329967a(12) =1511210765a(13) =9818610764a(14) =63966280085a(15) =417707613785
External references
- oeis: A390542