Largest prime factor of 12^n+1.

Terms

a(0) =2a(1) =13a(2) =29a(3) =19a(4) =233a(5) =19141a(6) =20593a(7) =13063a(8) =260753a(9) =1801a(10) =85403261a(11) =57154490053a(12) =2227777a(13) =222379a(14) =13156924369a(15) =35671a(18) =122138321401a(19) =905265296671a(20) =67657441a(21) =1885339a(22) =68368660537a(24) =592734049a(25) =438472201