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A160773 Numbers n such that 3^n + 5^n + 7^n is prime. 3
0, 2, 10, 14, 24, 26, 126, 514, 522, 1658, 13758, 77194 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Note that n must be even.

REFERENCES

Joao Carlos Leandro da Silva, The Rainbow of Primes, Freund Publishing House, Tel Aviv, 2009.

LINKS

Table of n, a(n) for n=1..12.

EXAMPLE

For n=2 we obtain f(2)= 3^2 + 5^2 + 7^2 = 83 which is a prime.

MAPLE

A160773:=n->`if`(isprime(3^n+5^n+7^n), n, NULL): seq(A160773(n), n=0..1000); # Wesley Ivan Hurt, Sep 19 2014

MATHEMATICA

Select[Range[0, 1000], PrimeQ[3^# + 5^# + 7^#] &] (* Wesley Ivan Hurt, Sep 19 2014 *)

PROG

(PARI) isok(n) = isprime(3^n + 5^n + 7^n) \\ Michel Marcus, Jul 25 2013

CROSSREFS

Sequence in context: A032624 A091999 A230624 * A217191 A190043 A217681

Adjacent sequences:  A160770 A160771 A160772 * A160774 A160775 A160776

KEYWORD

nice,nonn,more

AUTHOR

Joao Carlos Leandro da Silva (zxawyh66(AT)yahoo.com), May 26 2009, Jun 01 2009

EXTENSIONS

Zero added by Zak Seidov, Oct 10 2009

STATUS

approved

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Last modified May 26 22:18 EDT 2017. Contains 287172 sequences.