a(n) = Sum_{k=0..n} k*binomial(4*n+2,2*k).
A306609
a(n) = Sum_{k=0..n} k*binomial(4*n+2,2*k).
Terms
- a(0) =0a(1) =15a(2) =465a(3) =11102a(4) =236997a(5) =4751010a(6) =91474890a(7) =1712391420a(8) =31398038701a(9) =566621243642
External references
- oeis: A306609