a(n) = (4*n)!/(3*n)! * Sum_{k=1..n} 1/(3*n+k).
A384137
a(n) = (4*n)!/(3*n)! * Sum_{k=1..n} 1/(3*n+k).
Terms
- a(0) =1a(1) =15a(2) =362a(3) =12122a(4) =520024a(5) =27216936a(6) =1681732464a(7) =119823343440
External references
- oeis: A384137
A384137
a(n) = (4*n)!/(3*n)! * Sum_{k=1..n} 1/(3*n+k).