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A199218 Prime XOR couples of A199217. 3

%I

%S 3,7,13,31,29,59,53,113,109,103,233,227,211,193,499,491,487,461,457,

%T 431,421,419,409,401,389,1013,967,937,929,919,883,877,863,859,853,827,

%U 809,797,2039,2011,2003,1979,1949,1901,1879,1871,1823,1789,1783,1753,1699

%N Prime XOR couples of A199217.

%C The terms are listed in generated, not numerical, order so that coupled terms in A199217 have the same index value.

%H Vincenzo Librandi, <a href="/A199218/b199218.txt">Table of n, a(n) for n = 1..1500</a>

%o (MAGMA)

%o XOR := func<a, b | Seqint([ (adigs[i] + bdigs[i]) mod 2 : i in [1..n]], 2)

%o where adigs := Intseq(a, 2, n)

%o where bdigs := Intseq(b, 2, n)

%o where n := 1 + Ilog2(Max([a, b, 1]))>;

%o for i in [1 .. 12] do

%o xornum:=2^(i)-2;

%o for j := 2^(i) +1 to 3*2^(i-1) by 2 do

%o xorcouple:=XOR(j,xornum);

%o if (IsPrime(j) and IsPrime(xorcouple)) then xorcouple;

%o end if;

%o end for;

%o "****";

%o end for;

%Y Cf. A199217.

%K nonn

%O 1,1

%A _Brad Clardy_, Nov 04 2011

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Last modified October 27 20:17 EDT 2021. Contains 348290 sequences. (Running on oeis4.)