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A194257 Primes of the form p^6 + p^5 + p^4 + p^3 + p^2 + p + 1 when p is prime. 6
127, 1093, 19531, 5229043, 25646167, 917087137, 52379047267, 153436090543, 502628805631, 11016462577051, 18871143464293, 251059142817757, 1812169199976451, 1940350890330343 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

These primes are generated by exactly A163268.

This sequence is included in A088550.

These numbers are repunit primes 1111111_n, so they are Brazilian primes and are terms of A085104.

Subsequence of A088550. - Hartmut F. W. Hoft, May 05 2017

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A193574(A163268(n)^6). - Hartmut F. W. Hoft, May 08 2017

MAPLE

select(isprime, map(p -> add(p^i, i=0..6), select(isprime, [2, seq(i, i=3..1000, 2)]))); # Robert Israel, May 05 2017

MATHEMATICA

a194257[n_] := Select[Map[(Prime[#]^7-1)/(Prime[#]-1)&, Range[n]], PrimeQ]

a194257[70] (* data *) (* Hartmut F. W. Hoft, May 05 2017 *)

CROSSREFS

Cf. A085104, A088550, A100330, A163268.

Sequence in context: A160897 A038994 A068023 * A243529 A299718 A300339

Adjacent sequences:  A194254 A194255 A194256 * A194258 A194259 A194260

KEYWORD

nonn

AUTHOR

Bernard Schott, Dec 21 2012

STATUS

approved

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Last modified April 18 16:41 EDT 2019. Contains 322209 sequences. (Running on oeis4.)