a(n) = 2^((n^2-n-2)/2)*(n+2)!A185970a(n) = 2^((n^2-n-2)/2)*(n+2)!Terms a(0) =1a(1) =3a(2) =24a(3) =480a(4) =23040a(5) =2580480a(6) =660602880a(7) =380507258880External referencesoeis: A185970