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A111489
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Numbers n such that the n-th composite number + the n-th prime number is prime.
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0
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13, 31, 47, 67, 79, 89, 97, 103, 113, 149, 173, 179, 211, 223, 241, 277, 313, 349, 359, 379, 449, 457, 487, 503, 509, 631, 743, 769, 797, 809, 887, 937, 967, 1009, 1049, 1109, 1123, 1213, 1231, 1277, 1289, 1319, 1409, 1429, 1453, 1471, 1489, 1543, 1571, 1663
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Conjecture: The number of primes in this sequence is infinite.
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EXAMPLE
| The third prime is 5, the third composite is 8, 8+5=13, the first entry.
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PROG
| (PARI) g(n)=for(x=1, n, y=prime(x)+composite(x); if(isprime(y), print1(y", ")))
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CROSSREFS
| Sequence in context: A080387 A097443 A100589 * A106294 A101649 A063305
Adjacent sequences: A111486 A111487 A111488 * A111490 A111491 A111492
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KEYWORD
| easy,nonn
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AUTHOR
| Cino Hilliard (hillcino368(AT)gmail.com), Nov 15 2005
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