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%I A092967
%S A092967 2,3,7,7,31,31,211,211,211,211,2311,2311,6007,6007,6007,6007,102103,
%T A092967 102103,3233231,3233231,3233231,3233231,17160991
%N A092967 Largest prime of the form a squarefree number + 1 where the prime divisors 
               of the squarefree number are < n.
%C A092967 Conjecture: a(n)-1 has prime(n) -1 divisors. Subsidiary sequence: Number 
               of primes of the from 2*p*q*r*...+ 1 where p,q,r etc. are distinct 
               odd primes < n.
%e A092967 a(13) =6007= 2*3*7*11*13 + 1, as 2*5*7*11*13+ 1 etc. are composite.
%t A092967 <<DiscreteMath`; <<NumberTheory`; Do[l = Select[Map[Times @@ #&, Subsets[Range[n]]], 
               SquareFreeQ]; Print[Max[Select[Map[ #+1&, l], PrimeQ]]], {n, 1, 30}] 
               (Propper)
%Y A092967 Cf. A092965, A060957.
%Y A092967 Sequence in context: A027672 A104138 A083809 this_sequence A056431 A011027 
               A100072
%Y A092967 Adjacent sequences: A092964 A092965 A092966 this_sequence A092968 A092969 
               A092970
%K A092967 nonn
%O A092967 1,1
%A A092967 Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Mar 26 2004
%E A092967 More terms from Ryan Propper (rpropper(AT)stanford.edu), Aug 13 2005

    
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Last modified November 27 22:38 EST 2009. Contains 167602 sequences.


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