The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A329727 Numbers k such that k^3 +- 2 and k +- 2 are prime. 2
 129, 1491, 1875, 2709, 5655, 6969, 10335, 14325, 14421, 17319, 26559, 35109, 37509, 43719, 50229, 52629, 101871, 102795, 104325, 105501, 120429, 127599, 132699, 136395, 137829, 157521, 172425, 173685, 179481, 186189, 191829, 211371, 219681, 221199, 229215, 234195 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS All terms in this sequence are divisible by 3. LINKS Daniel Starodubtsev, Table of n, a(n) for n = 1..10000 EXAMPLE a(1) = 129: 129^3 + 2 = 2146691; 129^3 - 2 = 2146687; 129 + 2 = 131; 129 - 2 = 127; all four results are prime. a(2) = 1491: 1491^3 + 2 = 3314613773; 1491^3 - 2 = 3314613769; 1491 + 2 = 1493; 1491 - 2 = 1489; all four results are prime. MATHEMATICA Select[Range[500000], PrimeQ[#^3 + 2] && PrimeQ[#^3 - 2] && PrimeQ[# + 2] && PrimeQ[# - 2] &] PROG (Magma) [k:k in [1..250000]|forall{m:m in [-2, 2]|IsPrime(k+m) and IsPrime(k^3+m)}]; // Marius A. Burtea, Nov 20 2019 (PARI) isok(k) = isprime(k-2) && isprime(k+2) && isprime(k^3-2) && isprime(k^3+2); \\ Michel Marcus, Nov 24 2019 (PARI) list(lim)=my(v=List(), p=127, k); forprime(q=131, lim+2, if(q-p==4 && isprime((k=p+2)^3-2) && isprime(k^3+2), listput(v, k)); p=q); Vec(v) \\ Charles R Greathouse IV, May 06 2020 CROSSREFS Intersection of A038599, A067200, and A087679. Cf. A040976, A052147, A090121, A268043, A268186. Sequence in context: A046286 A341552 A251095 * A209532 A233305 A268266 Adjacent sequences: A329724 A329725 A329726 * A329728 A329729 A329730 KEYWORD nonn AUTHOR K. D. Bajpai, Nov 19 2019 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified April 1 05:25 EDT 2023. Contains 361673 sequences. (Running on oeis4.)