a(0) = 1; thereafter a(n) = n*a(n-1)^2.A052129a(0) = 1; thereafter a(n) = n*a(n-1)^2.Terms a(0) =1a(1) =1a(2) =2a(3) =12a(4) =576a(5) =1658880External referencesoeis: A052129