a(n) = H(2n+1)*(2n+1)!/n!, where H(n) = Sum_{k=1..n} 1/k, the n-th harmonic number.

A124079

a(n) = H(2n+1)*(2n+1)!/n!, where H(n) = Sum_{k=1..n} 1/k, the n-th harmonic number.

Terms

    a(0) =1a(1) =11a(2) =137a(3) =2178a(4) =42774a(5) =1004532a(6) =27503832a(7) =860945040a(8) =30342400560

External references