a(n) = (A203768(n+2) - 1)/2.A203769a(n) = (A203768(n+2) - 1)/2.Terms a(0) =0a(1) =0a(2) =1a(3) =5a(4) =30a(5) =479a(6) =35369a(7) =36141988External referencesoeis: A203769