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A245640
Prime numbers P such that 24*P^3-1 is also prime.
4
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
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
Sequence in context: A096478 A342244 A076047 * A365274 A178766 A362778
KEYWORD
nonn,easy
AUTHOR
Pierre CAMI, Jul 28 2014
STATUS
approved