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A273947 Prime factors of generalized Fermat numbers of the form 6^(2^m) + 1 with m >= 0.

%I A273947 #19 Jan 08 2025 11:02:36
%S A273947 7,17,37,257,353,1297,1697,2753,18433,65537,80897,98801,145601,763649,
%T A273947 3360769,4709377,13631489,50307329,376037377,2483027969,3191106049,
%U A273947 4926056449,51808043009,152605556737,916326983681,1268357529601,6597069766657,40711978221569
%N A273947 Prime factors of generalized Fermat numbers of the form 6^(2^m) + 1 with m >= 0.
%C A273947 Primes p other than 5 such that the multiplicative order of 6 (mod p) is a power of 2.
%D A273947 Hans Riesel, Common prime factors of the numbers A_n=a^(2^n)+1, BIT 9 (1969), pp. 264-269.
%H A273947 Arkadiusz Wesolowski, <a href="/A273947/b273947.txt">Table of n, a(n) for n = 1..34</a>
%H A273947 Anders Björn and Hans Riesel, <a href="http://dx.doi.org/10.1090/S0025-5718-98-00891-6">Factors of generalized Fermat numbers</a>, Math. Comp. 67 (1998), no. 221, pp. 441-446.
%H A273947 Anders Björn and Hans Riesel, <a href="http://dx.doi.org/10.1090/S0025-5718-05-01816-8">Table errata to “Factors of generalized Fermat numbers”</a>, Math. Comp. 74 (2005), no. 252, p. 2099.
%H A273947 Anders Björn and Hans Riesel, <a href="http://dx.doi.org/10.1090/S0025-5718-10-02371-9">Table errata 2 to "Factors of generalized Fermat numbers"</a>, Math. Comp. 80 (2011), pp. 1865-1866.
%H A273947 C. K. Caldwell, Top Twenty page, <a href="https://t5k.org/top20/page.php?id=9">Generalized Fermat Divisors (base=6)</a>
%H A273947 Harvey Dubner and Wilfrid Keller, <a href="http://dx.doi.org/10.1090/S0025-5718-1995-1270618-1">Factors of Generalized Fermat Numbers</a>, Math. Comp. 64 (1995), no. 209, pp. 397-405.
%H A273947 OEIS Wiki, <a href="/wiki/Generalized_Fermat_numbers">Generalized Fermat numbers</a>
%H A273947 Hans Riesel, <a href="https://doi.org/10.1090/S0025-5718-1969-0245507-6">Some factors of the numbers G_n=6^(2^n)+1 and H_n=10^(2^n)+1</a>, Math. Comp. 23 (1969), no. 106, pp. 413-415.
%t A273947 Select[Prime@Range[4, 10^5], IntegerQ@Log[2, MultiplicativeOrder[6, #]] &]
%Y A273947 Cf. A023394, A072982, A078303, A268663, A273945 (base 3), A273946 (base 5), A273948 (base 7), A273949 (base 11), A273950 (base 12).
%K A273947 nonn
%O A273947 1,1
%A A273947 _Arkadiusz Wesolowski_, Jun 05 2016