OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
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
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Nov 06 2020
STATUS
approved