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%I #15 Jul 08 2019 02:02:27
%S 563,1103,2467,2819,6599,29339,41039,52631,62743,172079,188459,278543,
%T 340559,488879,656599,656603,670031,1033667,1909003,2100899,3146219,
%U 5048999,6049679,8719307,10024559,10402559,10877579,11119103,12261059,14913989,15247619
%N Primes with a twin Carmichael number: primes p such that p-2 or p+2 are Carmichael numbers.
%H Amiram Eldar, <a href="/A135437/b135437.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1878 from Pierre CAMI)
%e 563 is in the sequence since it is a prime number, and 563 - 2 = 561 is a Carmichael number.
%e 1103 is in the sequence since it is a prime number, and 1103 + 2 = 1105 is a Carmichael number.
%t s = {}; carmichaelQ[n_] := CompositeQ[n] && Divisible[n - 1, CarmichaelLambda[n]]; Do[If[carmichaelQ[n], If[PrimeQ[n - 2], AppendTo[s, n - 2]]; If[PrimeQ[n + 2], AppendTo[s, n + 2]]], {n, 10^6}]; s (* _Amiram Eldar_, Jul 07 2019 *)
%Y Cf. A002997, A287591.
%K nonn
%O 1,1
%A _Pierre CAMI_, Dec 14 2007, corrected Jun 22 2008; Sep 17 2008
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