This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A277048 #17 Sep 08 2022 08:46:17 %S A277048 11,13,23,47,59,83,107,167,179,227,263,347,359,383,431,467,479,503, %T A277048 563,587,683,719,839,863,887,983,1019,1091,1093,1187,1223,1283,1307, %U A277048 1319,1367,1439,1487,1511,1523,1583,1597,1619,1669,1823,1871,1907,2027 %N A277048 Primes p such that the multiplicative order of 3 modulo p is prime. %C A277048 Odd primes that divide 3^p-1 for some prime p. - _Robert Israel_, Nov 14 2016 %H A277048 Robert Israel, <a href="/A277048/b277048.txt">Table of n, a(n) for n = 1..10000</a> %p A277048 select(p -> isprime(p) and isprime(numtheory:-order(3, p)), [seq(p, p=5..10000, 2)]); # _Robert Israel_, Nov 14 2016 %t A277048 Select[Prime@ Range@ 310, PrimeQ@ MultiplicativeOrder[3, #] &] (* _Michael De Vlieger_, Oct 28 2016 *) %o A277048 (Magma) [p: p in PrimesInInterval(2, 4000) | IsPrime(Modorder(3, p))]; %o A277048 (PARI) isok(n) = isprime(n) && isprime(znorder(Mod(3,n))); \\ _Michel Marcus_, Oct 28 2016 %Y A277048 Cf. A000040, A122094. %K A277048 nonn %O A277048 1,1 %A A277048 _Vincenzo Librandi_, Oct 28 2016