OFFSET
0,1
LINKS
S. S. Wagstaff, Jr., The Cunningham Project
FORMULA
EXAMPLE
7^12 + 1 = 2*73*193*409*1201, so a(12) = 1201.
MATHEMATICA
Table[FactorInteger[7^n + 1][[-1, 1]], {n, 0, 30}] (* Bruno Berselli, Aug 23 2013 *)
PROG
(PARI) a(n) = f = factor(7^n + 1); f[#f~, 1]; \\ Michel Marcus, Aug 22 2013
(Magma) [Maximum(PrimeDivisors(7^n+1)): n in [0..30]]; // Bruno Berselli, Aug 23 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Marcus, Aug 22 2013
EXTENSIONS
Terms to a(100) in b-file from Vincenzo Librandi, Jul 12 2016
a(101)-a(372) in b-file from Amiram Eldar, Feb 02 2020
a(373)-a(387) in b-file from Max Alekseyev, Apr 25 2022, Aug 30 2023
STATUS
approved