A302987 Primes p such that p+3 divides 3^p+3.

3, 7, 727, 1595287, 3773335151, 53968982887, 218662611751, 373627441111, 525882352087, 612618285511

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