login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A163268 Primes p such that 1 + p + p^2 + p^3 + p^4 + p^5 + p^6 is prime. 4
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 (list; graph; refs; listen; history; text; internal format)
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

PROG

(PARI) n=0; forprime(p=2, 10000, isprime((p^7-1)/(p-1))&&print(n++" "p))\\ Zak Seidov, Mar 09 2013

CROSSREFS

Cf. A053182, A065509, A088550, A100330, A163268, A194257.

Sequence in context: A105879 A066111 A065820 * A235624 A108562 A087523

Adjacent sequences:  A163265 A163266 A163267 * A163269 A163270 A163271

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, Jul 24 2009

EXTENSIONS

Edited (but not checked) by N. J. A. Sloane, Jul 25 2009

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 26 00:37 EDT 2019. Contains 321479 sequences. (Running on oeis4.)