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 A302987 Primes p such that p+3 divides 3^p+3. 1
 3, 7, 727, 1595287, 3773335151, 53968982887, 218662611751, 373627441111, 525882352087, 612618285511 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Conjecture: the sequence is finite. Is this the same as the primes in A251862? - Michel Marcus, Apr 17 2018 a(11) > 10^12, if it exists. - Giovanni Resta, Apr 17 2018 LINKS Table of n, a(n) for n=1..10. MATHEMATICA Select[Prime[Range[10000]], Divisible[3^# + 3, # + 3] &] (* Vincenzo Librandi, Apr 17 2018 *) PROG (PARI) isok(p) = isprime(p) && (Mod(3, p+3)^p == Mod(-3, p+3)); \\ Michel Marcus, Apr 17 2018 CROSSREFS Cf. A000040, A000244, A302988. Sequence in context: A062599 A101246 A056801 * A092568 A055624 A065244 Adjacent sequences: A302984 A302985 A302986 * A302988 A302989 A302990 KEYWORD nonn,hard,more AUTHOR Alex Ratushnyak, Apr 17 2018 EXTENSIONS a(4)-a(5) from Michel Marcus, Apr 17 2018 a(6)-a(10) from Giovanni Resta, Apr 17 2018 STATUS approved

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Last modified August 9 05:47 EDT 2024. Contains 375027 sequences. (Running on oeis4.)