a(n) = 2^(2^n-1) - 2^n - 1.A103743a(n) = 2^(2^n-1) - 2^n - 1.Terms a(0) =-1a(1) =-1a(2) =3a(3) =119a(4) =32751a(5) =2147483615External referencesoeis: A103743