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A227049 Numbers n such that (15^n + 4^n)/19 is prime. 2
3, 31, 157, 239, 1553, 5521, 25561 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
All terms are primes.
a(8) > 10^5.
LINKS
MATHEMATICA
Select[ Prime[ Range[1, 100000] ], PrimeQ[ (15^# + 4^#)/19 ]& ]
PROG
(PARI) is(n)=ispseudoprime((15^n+4^n)/19) \\ Charles R Greathouse IV, Jun 06 2017
CROSSREFS
Sequence in context: A087389 A294394 A064055 * A078604 A195603 A089286
KEYWORD
hard,nonn,more
AUTHOR
Robert Price, Jun 29 2013
STATUS
approved

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Last modified March 28 10:55 EDT 2024. Contains 371241 sequences. (Running on oeis4.)