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A137839
Least prime P such that 3*p(n)*P*(3*p(n)*P+1)-1, 3*p(n)*P*(3*p(n)*P+1)+1,3*p(n)*P*(3*p(n)*P+3)-1,3*p(n)*P*(3*p(n)*P+3)+1 are all primes with p(i) = i-th prime.
1
3109, 14537, 5879, 79, 6203, 22307, 12569, 2749, 2647, 2767, 15061, 33713, 64693, 420851, 12743, 125941, 119179, 640771, 171329, 75793, 58027, 7, 129341, 4409, 10093, 18301, 21817, 7253, 58109, 4271, 86599, 211723, 7703, 238339, 90437, 136991, 13619, 1607, 4639
OFFSET
1,1
LINKS
MAPLE
f:= proc(p) local k;
k:= 1:
do
k:= nextprime(k);
if isprime(3*p*k*(3*p*k+1)-1) and
isprime(3*p*k*(3*p*k+1)+1) and
isprime(3*p*k*(3*p*k+3)-1) and
isprime(3*p*k*(3*p*k+3)+1) then return k
fi
od
end proc:
map(f, [seq(ithprime(i), i=1..50)]); # Robert Israel, Jan 04 2021
CROSSREFS
Sequence in context: A257356 A187593 A230923 * A343373 A238513 A357957
KEYWORD
nonn
AUTHOR
Pierre CAMI, Apr 29 2008
EXTENSIONS
Corrected and extended by D. S. McNeil, Dec 10 2010
STATUS
approved