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 A211409 Numbers n such that (9^n + 4^n)/13 is prime. 1
 3, 5, 7, 11, 17, 19, 41, 53, 109, 167, 2207, 3623, 5059, 5471, 7949, 21211, 32993, 60251 (list; graph; refs; listen; history; text; internal format)
 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 cf. A181141, A128339, A057175, A125956, A187819. Sequence in context: A235476 A094342 A045397 * A152998 A222176 A108539 Adjacent sequences:  A211406 A211407 A211408 * A211410 A211411 A211412 KEYWORD more,nonn AUTHOR Robert Price, Feb 09 2013 STATUS approved

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Last modified May 26 00:04 EDT 2019. Contains 323576 sequences. (Running on oeis4.)