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%I #10 Jan 27 2014 22:09:42
%S 2,2,3,3,2,13,2,11,19,2,2,5,11,2,31,53,3,31,43,19,13,11,43,23,7,5,13,
%T 5,29,2,29,17,53,157,13,13,3,5,127,7,97,5,97,2,89,61,7,71,61,5,127,
%U 113,37,191,107,17,197,37,101,2,5,7,17,457,3,19,29,103,227
%N Smallest prime a(n) such that 1 + a(1)*a(2)*...*a(n) is prime.
%H Giovanni Resta, <a href="/A236465/b236465.txt">Table of n, a(n) for n = 1..500</a>
%e a(1) = 2 because 1 + 2 = 3, which is prime.
%e a(2) = 2 because 1 + 2 * 2 = 5, which is prime.
%e a(3) = 3 because 2 doesn't work, since 1 + 2 * 2 * 2 = 9 = 3^2, but 3 does work, giving 1 + 2 * 2 * 3 = 13, which is prime.
%t pr = 1; Table[p = 2; While[! PrimeQ[p * pr + 1], p = NextPrime@p]; pr *= p; p, {n, 100}] (* _Giovanni Resta_, Jan 26 2014 *)
%Y Cf. A036012, A039726.
%K nonn
%O 1,1
%A _Thomas Ordowski_, Jan 26 2014
%E a(11)-a(69) from _Giovanni Resta_, Jan 26 2014
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