|
|
A274905
|
|
Largest prime factor of 8^n + 1.
|
|
5
|
|
|
2, 3, 13, 19, 241, 331, 109, 5419, 673, 87211, 1321, 20857, 38737, 22366891, 14449, 18837001, 22253377, 43691, 279073, 160465489, 4562284561, 77158673929, 4327489, 168749965921, 487824887233, 1133836730401, 21841, 272010961, 88959882481, 96076791871613611
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,1
|
|
LINKS
|
J. Brillhart et al., Factorizations of b^n +- 1, Contemporary Mathematics, Vol. 22, Amer. Math. Soc., Providence, RI, 3rd edition, 2002.
|
|
FORMULA
|
|
|
MAPLE
|
8^4 + 1 = 4097 = 17*241, so a(4) = 241.
|
|
MATHEMATICA
|
Table[FactorInteger[8^n + 1][[-1, 1]], {n, 0, 40}]
|
|
PROG
|
(Magma) [Maximum(PrimeDivisors(8^n+1)): n in [0..40]];
|
|
CROSSREFS
|
Cf. similar sequences listed in A274903.
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
a(355)-a(502) in b-file from Max Alekseyev, May 28 2022, Sep 06 2022, Feb 25 2023
|
|
STATUS
|
approved
|
|
|
|