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%I #40 Oct 26 2023 23:36:59
%S 5,5,19,61,3221,37,45319,7321,1772893,13421,1806113,1117,3158528101,
%T 1623931,195019441,6304673,50544702849929377,1772893,
%U 6115909044841454629,212601841,45319,1806113,3740221981231,20113,1856458657451,3158528101,5559917315850179173
%N Largest prime factor of 11^n - 1.
%H <a href="/A274910/b274910.txt">Table of n, a(n) for n = 1..316</a>
%H J. Brillhart et al., <a href="http://dx.doi.org/10.1090/conm/022">Factorizations of b^n +- 1</a>, Contemporary Mathematics, Vol. 22, Amer. Math. Soc., Providence, RI, 3rd edition, 2002.
%F a(n) = A006530(A024127(n)).
%e 11^4 - 1 = 14640 = 2^4*3*5*61, so a(4) = 61.
%t Table[FactorInteger[11^n - 1][[-1, 1]], {n, 40}]
%o (Magma) [Maximum(PrimeDivisors(11^n-1)): n in [1..40]];
%Y Cf. A006530, A024127.
%Y Cf. similar sequences listed in A274906.
%K nonn
%O 1,1
%A _Vincenzo Librandi_, Jul 11 2016
%E Terms to a(70) in b-file from _Vincenzo Librandi_, Jul 13 2016
%E a(71)-a(306) in b-file from _Amiram Eldar_, Feb 08 2020
%E a(307)-a(316) in b-file from _Max Alekseyev_, Apr 25 2022, Oct 26 2023
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