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Search: id:A163431
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| A163431 |
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Primes p such that floor(p^3/8) are also prime numbers. |
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+0
4
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| 3, 19, 83, 179, 191, 239, 373, 431, 643, 719, 739, 883, 1123, 1151, 1171, 1237, 1283, 1429, 1459, 1669, 1811, 2053, 2083, 2293, 2351, 2437, 2579, 2677, 2687, 2819, 2851, 2879, 3167, 3253, 3491, 3539, 3877, 4051, 4099, 4483, 4549, 4643, 4799, 5087, 5171
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OFFSET
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1,1
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FORMULA
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A163430(n) = floor( a(n)^3/8 ).
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EXAMPLE
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a(1)=p=3 generates (3^3/8=3.375 where 3 isprime. a(2)=19 generates (19^3/8=857.275 where 857 is prime.
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MATHEMATICA
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f[n_]:=IntegerPart[(p/2)^3]; lst={}; Do[p=Prime[n]; If[PrimeQ[f[p]], AppendTo[lst, p]], {n, 7!}]; lst
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CROSSREFS
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Sequence in context: A093734 A099421 A061171 this_sequence A167242 A089621 A015528
Adjacent sequences: A163428 A163429 A163430 this_sequence A163432 A163433 A163434
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KEYWORD
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nonn
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AUTHOR
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Vladimir Orlovsky (4vladimir(AT)gmail.com), Jul 27 2009
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EXTENSIONS
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Mathematica specific notation removed, comments moved to examples - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 17 2009
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