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A126263 List of primes generated by factoring successive integers in Sylvester's sequence (A000058). 5

%I

%S 2,3,7,43,13,139,3263443,547,607,1033,31051,29881,67003,9119521,

%T 6212157481,5295435634831,31401519357481261,77366930214021991992277,

%U 181,1987,112374829138729,114152531605972711,35874380272246624152764569191134894955972560447869169859142453622851

%N List of primes generated by factoring successive integers in Sylvester's sequence (A000058).

%C The list is infinite and no term repeats since Sylvester's sequence is an infinite coprime sequence.

%D F. Saidak, A New Proof of Euclid's Theorem, American Mathematical Monthly, December 2006

%H William Stein, <a href="/A126263/b126263.txt">Table of n, a(n) for n = 1..27</a>

%H Filip Saidak, <a href="http://primes.utm.edu/notes/proofs/infinite/Saidak.html">Proof of Euclid's Theorem</a>.

%e 2 = 2, 3 = 3, 7 = 7, 43 = 43, 1807 = 13 * 139, 3263443 = 3263443,

%e 10650056950807 = 547 * 607 * 1033 * 31051,

%e 113423713055421844361000443 = 29881 * 67003 * 9119521 * 6212157481,

%e 12864938683278671740537145998360961546653259485195807 = 5295435634831 * 31401519357481261 * 77366930214021991992277.

%e 165506647324519964198468195444439180017513152706377497841851388766535868639572406808911988131737645185443 = 181 * 1987 * 112374829138729 * 114152531605972711 * 35874380272246624152764569191134894955972560447869169859142453622851. - _Jonathan Sondow_, Jan 26 2014

%p a(0):=2; for n from 0 to 8 do a(n+1):=a(n)^2-a(n)+1;ifactor(%); od;

%o (Sage) # program from William Stein, Aug 26 2009

%o v=[2]

%o for n in range(12):

%o ... v.append(v[-1]^2-v[-1]+1)

%o ... print prime_divisors(v[-1])

%o (PARI) vecprod(v)=prod(i=1,#v,v[i])

%o v=[2]; for(i=1,10, v=concat(v,Set(factor(vecprod(v)+1)[,1]))); v \\ _Charles R Greathouse IV_, Oct 02 2014

%Y Cf. A000058, A007996, A236433.

%K nonn

%O 1,1

%A Howard L. Warth (hlw6c2(AT)umr.edu), Dec 22 2006

%E Offset corrected by _N. J. A. Sloane_, Aug 20 2009

%E a(23) - a(27) from William Stein (wstein(AT)gmail.com), Aug 20 2009, Aug 21 2009

%E a(17) corrected by _D. S. McNeil_, Dec 10 2010

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Last modified December 20 09:43 EST 2014. Contains 252241 sequences.