login
A368691
Primes p such that p + 4 * q is prime, where q is the next prime after p.
1
3, 23, 31, 73, 83, 157, 167, 211, 251, 353, 373, 443, 467, 503, 509, 523, 541, 571, 647, 727, 751, 941, 947, 977, 1033, 1069, 1123, 1201, 1259, 1361, 1381, 1493, 1511, 1531, 1553, 1613, 1759, 1811, 2011, 2207, 2333, 2351, 2383, 2399, 2417, 2543, 2777, 2927, 3061, 3067, 3083, 3301, 3331, 3511
OFFSET
1,1
LINKS
EXAMPLE
a(3) = 31 is a term because 31 is prime, the next prime is 37, and 31 + 4 * 37 = 179 is prime.
MAPLE
filter:= proc(p) local q;
if not isprime(p) then return false fi;
q:= nextprime(p);
isprime(p+4*q)
end proc:
select(filter, [seq(i, i=3..10000, 2)]);
MATHEMATICA
f[p_] := Module[{q}, If[!PrimeQ[p], Return[False]]; q = NextPrime[p]; PrimeQ[p + 4*q]]; Select[Range[3, 3511, 2], f] (* James C. McMahon, Jan 03 2024 *)
CROSSREFS
Cf. A175914.
Sequence in context: A191086 A058302 A133213 * A138465 A006598 A245623
KEYWORD
nonn
AUTHOR
Zak Seidov and Robert Israel, Jan 03 2024
STATUS
approved