A263309 Numbers n such that p=6n+1 and q=6p+1 are primes.

1, 2, 6, 10, 12, 17, 25, 30, 40, 45, 46, 47, 52, 55, 61, 62, 66, 96, 100, 101, 110, 121, 125, 131, 142, 151, 156, 172, 177, 186, 195, 200, 220, 221, 230, 237, 242, 255, 261, 282, 296, 305, 312, 331, 332, 356, 360, 367, 370, 380, 381, 382, 391, 425, 432, 446, 461, 465, 475, 495, 506, 510, 527, 530

Offset

1,2

Comments

Subsequence of A024899.

The subsequence of primes in this sequence is A023256.

Links

Table of n, a(n) for n=1..64.

Maple

isA263309 := proc(n)
    if isprime(6*n+1) then
        if isprime(36*n+7) then
            true;
        else
            false;
        end if;
    else
        false;
    end if;
end proc:
for n from 1 to 100 do
    if isA263309(n) then
        printf("%d, ", n);
    end if;
end do: # R. J. Mathar, Oct 17 2015

Mathematica

Select[Range[1000], PrimeQ[p=6*#+1]&& PrimeQ[q=6*p+1]&]

Prog

(PARI) isok(n) = isprime(p=6*n+1) && isprime(6*p+1); \\ Michel Marcus, Oct 17 2015

Crossrefs

Cf. A023256, A024899.

Sequence in context: A189395 A190003 A357702 * A253913 A190789 A071638

Adjacent sequences: A263306 A263307 A263308 * A263310 A263311 A263312

Keyword

nonn

Author

Zak Seidov, Oct 13 2015

Status

approved