A267455 - OEIS

%I #19 May 29 2025 06:08:53

%S 3,13,43,61,79,103,127,139,157,181,199,211,277,283,313,337,367,373,

%T 433,439,523,547,571,601,607,673,727,751,757,823,829,859,883,907,919,

%U 937,991,997,1039,1063,1069,1093,1117,1153,1171,1213,1231,1249,1291,1297,1303,1327,1381,1429,1447,1453,1459,1483

%N Primes which are a square (mod 39).

%C Motivated by the former (incorrect) definition of A191029.

%C Also, primes p which have Legendre symbols (p|3) = (p|13) = 1, together with 3 and 13.

%C Apparently this contains the 3 plus the elements of A139494. - _R. J. Mathar_, May 28 2025

%H Paolo Xausa, <a href="/A267455/b267455.txt">Table of n, a(n) for n = 1..10000</a>

%t Join[{3, 13}, Select[Prime[Range[500]], JacobiSymbol[#, {3, 13}] == {1, 1} &]] (* _Paolo Xausa_, May 29 2025 *)

%o (PARI) select(p->issquare(Mod(p,39))&&isprime(p),[1..1000])

%Y Cf. A038889, A045373, A056874, A106863, A106881, A191029.

%Y Cf. A139494.

%K nonn,easy

%O 1,1

%A _M. F. Hasler_, Jan 15 2016