Smallest prime factor of A020549(n) = (n!)^2 + 1.

Terms

a(0) =2a(1) =2a(2) =5a(3) =37a(4) =577a(5) =14401a(6) =13a(7) =101a(8) =17a(9) =131681894401a(12) =101a(14) =29a(15) =1344169a(16) =149a(17) =9049a(18) =37a(19) =710341a(20) =41a(21) =61a(22) =337a(23) =509a(25) =941