login
A145476
Primes p such that (19 + p)/2 is prime.
3
3, 7, 19, 43, 67, 103, 127, 139, 199, 283, 307, 367, 379, 439, 463, 523, 547, 607, 643, 727, 739, 823, 859, 907, 1063, 1123, 1303, 1327, 1399, 1447, 1459, 1483, 1627, 1699, 1747, 1999, 2083, 2239, 2287, 2383, 2539, 2887, 3067, 3079, 3307, 3319, 3463, 3499
OFFSET
1,1
COMMENTS
All these primes are congruent to 3 mod 4 and (with the exception of the first term) to 5 mod 12.
LINKS
MATHEMATICA
aa = {}; k = 19; Do[If[PrimeQ[(k + Prime[n])/2], AppendTo[aa, Prime[n]]], {n, 1, 500}]; aa
Select[Prime[Range[500]], PrimeQ[(#+19)/2]&] (* Harvey P. Dale, Sep 06 2023 *)
PROG
(PARI) list(n)=my(t=1, p, i=1); while(i<n, p=prime(i); i=i+1; if(p>2&&bigomega((19+p)/2)==1, print(p))) Anders Hellström, Jan 22 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Artur Jasinski, Oct 11 2008
STATUS
approved