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 A265486 Numbers n such that 64^n - 8^n - 1 is prime. 1
 3, 6, 15, 19, 36, 75, 80, 118, 199, 336, 360, 520, 1282, 1810, 2872, 4870, 14467, 15102, 22499, 24675, 45615, 105648, 116432 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS For n = 3, 6, 15, 19 the corresponding primes are 261631, 68719214591, 1237940039285345090527035391, 20769187434139310370006797241024511. 3*a(n) belongs to A098845 (the terms from a(18) to a(23) are derived from that sequence). LINKS EXAMPLE 3 is in the sequence because 64^3 - 8^3 - 1 = 261631 is prime. MATHEMATICA Select[Range[1000], PrimeQ[64^# - 8^# - 1] &] PROG (MAGMA) [n: n in [0..300] | IsPrime(64^n-8^n-1)]; (PARI) for(n=1, 1e3, if(ispseudoprime(64^n - 8^n - 1), print1(n, ", "))) \\ Altug Alkan, Dec 12 2015 CROSSREFS Cf. A098845, similar sequences listed in A265481. Sequence in context: A174279 A233554 A276546 * A060304 A342555 A075868 Adjacent sequences:  A265483 A265484 A265485 * A265487 A265488 A265489 KEYWORD nonn,more AUTHOR Vincenzo Librandi, Dec 12 2015 STATUS approved

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Last modified May 23 03:15 EDT 2022. Contains 353959 sequences. (Running on oeis4.)