cp's OEIS Frontend

A263310 Numbers n such that p=6*n+1, q=6*p+1 and r=6*q+1 are primes.

%I A263310 #11 Oct 17 2015 17:41:18
%S A263310 10,25,55,61,101,125,156,220,221,381,391,465,475,495,576,810,891,901,
%T A263310 975,1060,1145,1396,1430,1630,1650,1726,1795,1811,1881,1885,1915,2196,
%U A263310 2265,2335,2391,2405,2456,2536,2575,2636,2651,2820,2911,2915,2951,2965,3051,3211,3245,3335
%N A263310 Numbers n such that p=6*n+1, q=6*p+1 and r=6*q+1 are primes.
%C A263310 Subsequence of A263309 (and as such also of A024899).
%p A263310 isA263310 := proc(n)
%p A263310     return isprime(6*n+1) and isprime(36*n+7) and isprime(216*n+43) ;
%p A263310 end proc:
%p A263310 for n from 1 to 3000 do
%p A263310     if isA263310(n) then
%p A263310         printf("%d,",n);
%p A263310     end if;
%p A263310 end do: # _R. J. Mathar_, Oct 17 2015
%t A263310 Select[Range[10000],PrimeQ[p=6*#+1]&& PrimeQ[q=6*p+1]&& PrimeQ[r=6*q+1]&]
%o A263310 (PARI) for(n=1, 1e4, if(isprime(p=6*n+1)&&isprime(q=6*p+1)&&isprime(6*q+1), print1(n", "))) \\ _Altug Alkan_, Oct 17 2015
%Y A263310 Cf. A024899, A263309.
%K A263310 nonn
%O A263310 1,1
%A A263310 _Zak Seidov_, Oct 13 2015