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A338518
Primes p such that (p*s) mod q and (p*s) mod r are prime, where q,r,s are the next primes after p.
2
3, 29, 37, 41, 53, 71, 73, 83, 107, 149, 157, 173, 179, 197, 199, 277, 283, 311, 317, 367, 401, 433, 491, 499, 509, 563, 643, 683, 727, 769, 773, 809, 829, 839, 877, 953, 1013, 1063, 1097, 1109, 1153, 1171, 1181, 1297, 1307, 1361, 1367, 1399, 1439, 1453, 1511, 1543, 1553, 1567, 1747, 1847, 1913
OFFSET
1,1
LINKS
EXAMPLE
a(4) = 41 is a member because with p=41, q=43, r=47 and s=53 we have (41*53) mod 43 = 23 and (41*53) mod 47 = 11, and 23 and 11 are prime.
MAPLE
p2:= 2: p3:= 3: p4:= 5: R:= NULL: count:= 0:
while count < 100 do
p1:= p2; p2:= p3; p3:= p4;
p4:= nextprime(p4);
r2:= (p1*p4) mod p2;
r3:= (p1*p4) mod p3;
if isprime(r2) and isprime(r3) then
R:= R, p1; count:= count+1;
fi
od:
R;
CROSSREFS
Cf. A338751.
Sequence in context: A189571 A055062 A086174 * A178642 A125854 A167278
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Nov 06 2020
STATUS
approved