a(n) = Sum_{k=0..n-2} T(n,k) * T(n,k+2), with T given by A026714.
A027203
a(n) = Sum_{k=0..n-2} T(n,k) * T(n,k+2), with T given by A026714.
Terms
- a(0) =1a(1) =10a(2) =75a(3) =450a(4) =2814a(5) =15202a(6) =89623a(7) =466252a(8) =2677281a(9) =13691160a(10) =77546684a(11) =393047294a(12) =2209036094a(13) =11140807218a(14) =62325916869a(15) =313402240000
External references
- oeis: A027203