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%I #4 Mar 31 2012 10:23:47
%S 0,0,1,0,0,1,1,2,3,12,1,0,22,2,4,13,12,6,1,4,1,4,0,2,9,5,6,2,1,9,17,
%T 22,7,19,73,23,12,5,27,33,64,33,5,7,41,44,35,29,3,19,6,26,5,11,9,33,
%U 34,16,63,46,8,4,24,48,0,11,0,26,6,25,17,31,6,46,33,46,17,8,61,12,23,76,20,17
%N a(n) = minimal m >= 0 that makes primorial P(n)*2^m-1 prime.
%C The values of n in A103515
%e P(2)*2^0-1=5 is prime, so a(2)=0; P(9)*2^2-1=892371479 is prime, so a(9)=2;
%t nmax = 2^2048; npd = 2; n = 2; npd = npd*Prime[n]; While[npd < nmax, tn = 0; tt = 1; cp = npd*tt - 1; While[(cp > 1) && (! (PrimeQ[cp])), tn = tn + 1; tt = tt*2; cp = npd*tt - 1]; Print[tn]; n = n + 1; npd = npd*Prime[n]]
%Y Cf. A002110, A005234, A014545, A018239, A006794, A057704, A057705, A103513, A103515.
%K nonn
%O 2,8
%A _Lei Zhou_, Feb 15 2005
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