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%I #4 Mar 30 2012 17:22:46
%S 3,15,105,93081
%N a(n) is the least product of n odd primes m=p1*p2*...*pn, such that for all divisor d|2*m, d+2*m/d is prime.
%C 1. a(5) > 2*10^9 2. (C. Pomerance) The prime k-tuple conjecture implies a(n) exists for all n
%e 105=3*5*7 and 2*3*5*7+1, 3*5*7+2, 2*5*7+3, 2*3*7+5, 2*3*5+7, 2*3+5*7, 2*5+3*7, 2*7+3*5 are all primes and 105 is the smallest such integer which is the product of 3 odd primes, so a(3)=105
%K hard,more,nonn
%O 1,1
%A Kok Seng Chua (chuakokseng(AT)hotmail.com), Feb 23 2007
%E Typo in a(4) corrected by _T. D. Noe_, Aug 04 2010
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