A211409 - OEIS

A211409

Numbers n such that (9^n + 4^n)/13 is prime.

3, 5, 7, 11, 17, 19, 41, 53, 109, 167, 2207, 3623, 5059, 5471, 7949, 21211, 32993, 60251

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OFFSET

1,1

COMMENTS

All terms are prime.

The next element, a(19), is greater than 10^5.

LINKS

MATHEMATICA

Select[ Prime[ Range[1, 100000] ], PrimeQ[ (9^# + 4^#)/13 ]& ]

PROG

(PARI) is(n)=ispseudoprime((9^n+4^n)/13) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

KEYWORD

more,nonn

AUTHOR

Robert Price, Feb 09 2013

STATUS

approved