

A114301


Numbers n such that 2^n + 3^n + 5^n + 7^n is a prime number.


0




OFFSET

1,2


COMMENTS

All terms are odd.  Robert Israel, May 03 2018


LINKS

Table of n, a(n) for n=1..7.


EXAMPLE

2^3 + 3^3 + 5^3 + 7^3 = 503 (prime), thus 3 is in the sequence.


MAPLE

select(t > isprime(2^t+3^t+5^t+7^t), [seq(i, i=1..10000, 2)]); # Robert Israel, May 03 2018


MATHEMATICA

Do[If[PrimeQ[2^n+3^n+5^n+7^n], Print[n]], {n, 1, 5000}]


CROSSREFS

Sequence in context: A168591 A319190 A014015 * A258669 A192340 A326973
Adjacent sequences: A114298 A114299 A114300 * A114302 A114303 A114304


KEYWORD

hard,more,nonn


AUTHOR

Stefan Steinerberger, Feb 05 2006


EXTENSIONS

a(6) from Ryan Propper, Mar 24 2006
a(7) from Joao Carlos Leandro da Silva (zxawyh66(AT)yahoo.com), Jun 01 2009


STATUS

approved



