

A256302


Least prime p such that p+3*k*(k+1) is prime for all k=0,...,n.


1



2, 5, 5, 5, 11, 11, 11, 11, 11, 11, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23
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OFFSET

0,1


COMMENTS

Inspired by the socalled primegenerating polynomials.
Since p  3n(n+1) for n=p1, one has a(n) > p(n). Otherwise stated, a(p1) = p (as, e.g., for p=23) is optimal.


LINKS



PROG

(PARI) a(n)=forprime(p=1, , for(i=1, n, ispseudoprime(p+3*(i+1)*i)next(2)); return(p))


CROSSREFS



KEYWORD

nonn,more


AUTHOR



STATUS

approved



