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A163431 Primes p such that floor(p^3/8) are also prime numbers. 4
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

FORMULA

A163430(n) = floor( a(n)^3/8 ).

EXAMPLE

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.

MATHEMATICA

f[n_]:=IntegerPart[(p/2)^3]; lst={}; Do[p=Prime[n]; If[PrimeQ[f[p]], AppendTo[lst, p]], {n, 7!}]; lst

CROSSREFS

Sequence in context: A061171 A293561 A240286 * A167242 A089621 A204256

Adjacent sequences:  A163428 A163429 A163430 * A163432 A163433 A163434

KEYWORD

nonn,easy

AUTHOR

Vladimir Joseph Stephan Orlovsky, Jul 27 2009

EXTENSIONS

Mathematica specific notation removed, comments moved to examples - R. J. Mathar, Sep 17 2009

STATUS

approved

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Last modified May 28 21:37 EDT 2020. Contains 334690 sequences. (Running on oeis4.)