a(n) = Sum_{k=0..n} C(n, k)*C(n+k, k)/(2k-1), where C(n, k) denotes the binomial coefficient n!/(k!*(n-k)!).
A245769
a(n) = Sum_{k=0..n} C(n, k)*C(n+k, k)/(2k-1), where C(n, k) denotes the binomial coefficient n!/(k!*(n-k)!).
Terms
- a(0) =-1a(1) =1a(2) =7a(3) =25a(4) =87a(5) =329a(6) =1359a(7) =6001a(8) =27759a(9) =132689a(10) =649815a(11) =3242377a(12) =16421831a(13) =84196761a(14) =436129183a(15) =2278835681a(16) =11996748255a(17) =63568974241a(18) =338777252263
External references
- oeis: A245769