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%I A111489
%S A111489 13,31,47,67,79,89,97,103,113,149,173,179,211,223,241,277,313,349,359,
%T A111489 379,449,457,487,503,509,631,743,769,797,809,887,937,967,1009,1049,1109,
%U A111489 1123,1213,1231,1277,1289,1319,1409,1429,1453,1471,1489,1543,1571,1663
%N A111489 Numbers n such that the n-th composite number + the n-th prime number 
               is prime.
%C A111489 Conjecture: The number of primes in this sequence is infinite.
%e A111489 The third prime is 5, the third composite is 8, 8+5=13, the first entry.
%o A111489 (PARI) g(n)=for(x=1,n,y=prime(x)+composite(x);if(isprime(y),print1(y",
               ")))
%Y A111489 Sequence in context: A080387 A097443 A100589 this_sequence A106294 A101649 
               A063305
%Y A111489 Adjacent sequences: A111486 A111487 A111488 this_sequence A111490 A111491 
               A111492
%K A111489 easy,nonn
%O A111489 1,1
%A A111489 Cino Hilliard (hillcino368(AT)gmail.com), Nov 15 2005

    
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Last modified December 8 08:31 EST 2009. Contains 170430 sequences.


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