a(n) = (n!/2) * Sum_{k=1..n-1} A000593(k)*A000593(n-k)/(k*(n-k)).

A338787

a(n) = (n!/2) * Sum_{k=1..n-1} A000593(k)*A000593(n-k)/(k*(n-k)).

Terms

    a(0) =0a(1) =1a(2) =3a(3) =35a(4) =110a(5) =1594a(6) =8064a(7) =125292a(8) =684144a(9) =14215536a(10) =102769920a(11) =2367099360a(12) =18380943360a(13) =463602216960

External references