Smallest number k such that n! + k is a square.

Terms

a(0) =0a(1) =2a(2) =3a(3) =1a(4) =1a(5) =9a(6) =1a(7) =81a(8) =729a(9) =225a(10) =324a(11) =39169a(12) =82944a(13) =176400a(14) =215296a(15) =3444736a(16) =26167684a(17) =114349225a(18) =255004929a(19) =1158920361a(20) =11638526761a(21) =42128246889a(22) =191052974116a(23) =97216010329