a(n) = (n!)^2 + 1.A020549a(n) = (n!)^2 + 1.Terms a(0) =2a(1) =2a(2) =5a(3) =37a(4) =577a(5) =14401a(6) =518401a(7) =25401601a(8) =1625702401a(9) =131681894401External referencesoeis: A020549