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A163268
Primes p such that 1 + p + p^2 + p^3 + p^4 + p^5 + p^6 is prime.
5
2, 3, 5, 13, 17, 31, 61, 73, 89, 149, 163, 251, 349, 353, 461, 523, 599, 647, 863, 941, 947, 1087, 1117, 1229, 1277, 1291, 1297, 1409, 1439, 1489, 1567, 1579, 1609, 1627, 1753, 1783, 1831, 2039, 2131, 2293, 2531, 2609, 2753, 2861, 3037, 3163, 3167, 3299
OFFSET
1,1
COMMENTS
Primes in A100330. The generated prime numbers are exactly A194257. [Bernard Schott, Dec 21 2012]
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000 (first 102 terms from Zak Seidov)
MAPLE
select(p -> isprime(p) and isprime(1+p+p^2+p^3+p^4+p^5+p^6), [2, seq(i, i=3..10000, 2)]); # Robert Israel, May 05 2017
MATHEMATICA
f[n_]:=1+n+n^2+n^3+n^4+n^5+n^6; lst={}; Do[p=Prime[n]; If[PrimeQ[f[p]], AppendTo[lst, p]], {n, 7!}]; lst
Select[Prime[Range[500]], PrimeQ[Total[#^Range[0, 6]]]&] (* Harvey P. Dale, Jul 13 2022 *)
PROG
(PARI) n=0; forprime(p=2, 10000, isprime((p^7-1)/(p-1))&&print(n++" "p))\\ Zak Seidov, Mar 09 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Edited (but not checked) by N. J. A. Sloane, Jul 25 2009
STATUS
approved