A080443 Largest prime factor of 3^n+2.

3, 5, 11, 29, 83, 7, 43, 199, 6563, 127, 59051, 25307, 48313, 63773, 4782971, 14348909, 119243, 335429, 23203, 10613, 60089, 1224149, 795323, 919, 282429536483, 1583717027, 2541865828331, 693236134999, 174632003473

Offset: 0

Author

Hugo Pfoertner, Mar 21 2003

Keywords

• nonn

Links

• Hugo Pfoertner, Table of n, a(n) for n = 0..210 (first 100 terms from Harvey P. Dale)

Crossrefs

Cf. A051783, A057735, A080798, A081715.

Programs

Magma

[Max(PrimeDivisors(3^n+2)):n in [0..28]]; // Marius A. Burtea, Jul 12 2019

Mathematica

Table[FactorInteger[3^n+2][[-1,1]],{n,0,30}] (* Harvey P. Dale, Oct 21 2011 *)

PARI

for(n=0,28,f=factor(3^n+2);print1(f[#f[,1],1],", ")) \\ Hugo Pfoertner, Jul 12 2019

Extensions

Corrected by T. D. Noe, Nov 15 2006