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Search: id:A127305
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| A127305 |
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Primes p such that p + (sum of the prime factors of p-1 and p+1) is prime. |
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+0
1
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| 13, 47, 71, 101, 151, 193, 239, 241, 293, 331, 337, 359, 383, 397, 401, 421, 463, 487, 557, 577, 709, 773, 797, 821, 929, 1019, 1031, 1069, 1093, 1103, 1181, 1217, 1249, 1327, 1367, 1423, 1499, 1571, 1759, 1787, 1789, 1831, 1871, 1877, 1913, 1933, 2053
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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151 is prime, 150 = 2*3*5*5, 152 = 2*2*2*19. 151 + 2+3+5+5 + 2+2+2+19 = 191 is prime, hence 151 is a term.
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PROGRAM
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(MAGMA) [ p: p in PrimesInInterval(3, 2100) | IsPrime(&+[ &+[ k[1]*k[2]: k in Factorization(n)]: n in [p-1..p+1] ] ) ]; /* Klaus Brockhaus, Apr 06 2007 */
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CROSSREFS
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Sequence in context: A034462 A116476 A035340 this_sequence A001662 A031390 A113943
Adjacent sequences: A127302 A127303 A127304 this_sequence A127306 A127307 A127308
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KEYWORD
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nonn
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AUTHOR
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J. M. Bergot (thekingfishb(AT)yahoo.ca), Mar 28 2007
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EXTENSIONS
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Edited and extended by Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Apr 06 2007
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