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Search: id:A164625
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| A164625 |
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Primes p such that p+floor(p/2)+floor(p/3)+floor(p/5) is also prime. |
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+0
1
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| 2, 3, 7, 19, 83, 89, 127, 137, 139, 181, 251, 257, 311, 317, 373, 379, 449, 491, 499, 503, 509, 673, 733, 797, 853, 857, 863, 919, 971, 983, 1033, 1039, 1049, 1093, 1151, 1201, 1217, 1399, 1453, 1579, 1583, 1627, 1697, 1741, 1871, 1933, 1993, 2129, 2237, 2281
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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For p=7, 7+3+2+1=13 is prime, which admits 7=a(4) to the sequence.
For p=19, 19+9+6+3=37 is prime, which puts 19=a(5) into the sequence.
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MATHEMATICA
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lst={}; Do[p=Prime[n]; If[PrimeQ[p+Floor[p/2]+Floor[p/3]+Floor[p/5]], AppendTo[lst, p]], {n, 2*6!}]; lst
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CROSSREFS
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Cf. A038874, A049545, A097933, A164624
Sequence in context: A025563 A110887 A065060 this_sequence A079804 A110498 A006073
Adjacent sequences: A164622 A164623 A164624 this_sequence A164626 A164627 A164628
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KEYWORD
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nonn,easy
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AUTHOR
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Vladimir Orlovsky (4vladimir(AT)gmail.com), Aug 17 2009
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EXTENSIONS
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Coments rephrased as examples by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 20 2009
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