|
%I #23 Sep 08 2021 03:42:52
%S 3,11,17,5,47,89,101,197,29,263,521,1559,173,3011,71,641,1277,53,317,
%T 4583,617,4019,401,3041,41,479,3347,131,10427,4643,1301,419,6689,5531,
%U 281,55217,251,2417,4001,491,1601,3137,449,3617,107,2969,4211,6737,1061
%N Numbers that are a prime factor of a Carmichael number divisible by 3, listed in the order in which they appear in the prime factorizations of such Carmichael numbers.
%C Every term, other than a(1)=3, is a prime of the form 6*k - 1.
%H Charles R Greathouse IV, <a href="/A216911/b216911.txt">Table of n, a(n) for n = 1..3744</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/CarmichaelNumber.html">Carmichael Number</a>
%e The first few Carmichael numbers that are divisible by 3 (A258801), their prime factorizations, and the terms of this sequence are as follows:
%e .
%e m | A258801(m) & prime factorization | prime factors not appearing earlier
%e --+----------------------------------+----------------------------------------
%e 1 | 561 = 3 * 11 * 17 | a(1) = 3, a(2) = 11, a(3) = 17;
%e 2 | 62745 = 3 * 5 * 47 * 89 | a(4) = 5, a(5) = 47, a(6) = 89;
%e 3 | 656601 = 3 * 11 * 101 * 197 | a(7) = 101, a(8) = 197; ...
%Y Cf. A002997 (Carmichael numbers), A258801 (Carmichael numbers divisible by 3).
%K nonn
%O 1,1
%A _Marius Coman_, Sep 20 2012
%E a(26), a(34), a(43) corrected by _Charles R Greathouse IV_, Sep 20 2012
|
