Denominator of Sum_{k=1..n} H(k)*H(n+1-k), where H(k) is the k-th harmonic number (Sum_{j=1..k} 1/j).

A130895

Denominator of Sum_{k=1..n} H(k)*H(n+1-k), where H(k) is the k-th harmonic number (Sum_{j=1..k} 1/j).

Terms

    a(0) =1a(1) =1a(2) =12a(3) =3a(4) =45a(5) =18a(6) =560a(7) =2520a(8) =8400a(9) =225a(10) =207900a(11) =207900a(12) =840840a(13) =191100a(14) =7761600a(15) =50450400a(16) =15437822400a(17) =14034384a(18) =214885440a(19) =29331862560a(20) =645300976320a(21) =517068090a(22) =742096122768a(23) =463810076730a(25) =492206612040

External references