Largest prime divisor of Lucas(5*n), where Lucas(k) = A000032(k).

Terms

a(0) =11a(1) =41a(2) =31a(3) =2161a(4) =151a(5) =2521a(6) =911a(7) =3041a(8) =541a(9) =570601a(10) =39161a(11) =20641a(12) =24571a(13) =12317523121a(14) =18451a(16) =12760031a(17) =10783342081a(18) =87382901a(19) =5738108801a(20) =767131a(22) =686551a(24) =28143378001a(26) =119611