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A274910 Largest prime factor of 11^n - 1. 2
5, 5, 19, 61, 3221, 37, 45319, 7321, 1772893, 13421, 1806113, 1117, 3158528101, 1623931, 195019441, 6304673, 50544702849929377, 1772893, 6115909044841454629, 212601841, 45319, 1806113, 3740221981231, 20113, 1856458657451, 3158528101, 5559917315850179173 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..70

J. Brillhart et al., Factorizations of b^n +- 1, Contemporary Mathematics, Vol. 22, Amer. Math. Soc., Providence, RI, 3rd edition, 2002.

FORMULA

a(n) = A006530(A024127(n)).

EXAMPLE

11^4 - 1 = 14640 = 2^4*3*5*61, so a(4) = 61.

MATHEMATICA

Table[FactorInteger[11^n - 1][[-1, 1]], {n, 40}]

PROG

(MAGMA) [Maximum(PrimeDivisors(11^n-1)): n in [1..40]];

CROSSREFS

Cf. A006530, A024127.

Cf. similar sequences listed in A274906.

Sequence in context: A246983 A305514 A039914 * A201803 A151789 A302176

Adjacent sequences:  A274907 A274908 A274909 * A274911 A274912 A274913

KEYWORD

nonn

AUTHOR

Vincenzo Librandi, Jul 11 2016

STATUS

approved

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Last modified October 21 08:47 EDT 2019. Contains 328292 sequences. (Running on oeis4.)