Largest prime factor of Stirling numbers of first kind s(n,2) = A000254(n).

Terms

a(0) =3a(1) =11a(2) =5a(3) =137a(4) =7a(5) =11a(6) =761a(7) =7129a(8) =61a(9) =863a(10) =509a(11) =919a(12) =1117a(13) =41233a(14) =8431a(15) =1138979a(16) =39541a(17) =7440427a(18) =11167027a(19) =18858053a(20) =227a(21) =583859a(22) =467183a(23) =312408463a(24) =34395742267a(25) =215087a(26) =375035183a(27) =4990290163a(28) =17783a(30) =535919