A245640 Prime numbers P such that 24*P^3-1 is also prime.

2, 3, 5, 7, 13, 17, 43, 61, 67, 73, 97, 127, 131, 137, 167, 241, 281, 307, 353, 433, 463, 467, 541, 557, 631, 641, 647, 653, 661, 673, 683, 821, 853, 857, 907, 911, 991, 1033, 1063, 1103, 1117, 1123, 1291, 1307, 1433, 1453, 1511, 1523, 1553, 1567, 1571, 1597, 1601, 1607

Offset

1,1

Links

Pierre CAMI, Table of n, a(n) for n = 1..10000

Example

24*2^3-1=191 prime so a(1)=2.
24*3^3-1=647 prime so a(2)=3.

Mathematica

Select[Prime[Range[300]], PrimeQ[24 #^3 - 1] &] (* Vincenzo Librandi, Sep 07 2014 *)

Prog

(PFGW & SCRIPT)
SCRIPT
DIM n, 0
DIMS t
OPENFILEOUT myf, a(n).txt
LABEL loop1
SET n, n+1
SETS t, %d, %d\,; n; p(n)
PRP 24*p(n)^3-1, t
IF ISPRP THEN GOTO a
GOTO loop1
LABEL a
WRITE myf, t
GOTO loop1
(PARI) select(p->isprime(24*p^3-1), primes(300)) \\ Colin Barker, Jul 28 2014
(Magma) [p: p in PrimesUpTo(1700)| IsPrime(24*p^3-1)]; // Vincenzo Librandi, Sep 07 2014

Crossrefs

Cf. A245639, A245641.

Sequence in context: A096478 A342244 A076047 * A365274 A178766 A362778

Adjacent sequences: A245637 A245638 A245639 * A245641 A245642 A245643

Keyword

nonn,easy

Author

Pierre CAMI, Jul 28 2014

Status

approved