A248785 - OEIS

%I #17 Aug 14 2020 14:06:10

%S 948,1134,1500,2058,2856,3192,3846,3906,4842,5190,5502,6744,6888,7266,

%T 7392,7698,8586,8778,8850,9198,9558,10272,10500,10782,11658,11730,

%U 11760,12456,12738,13062,13578,14130,14262,14658,14808,15306,15552,15720,16104,16242

%N Numbers n with the property that p = n^2 - 13 and q = n^2 + 13 are consecutive primes.

%C All terms are == 0 (mod 6).

%H Zak Seidov, <a href="/A248785/b248785.txt">Table of n, a(n) for n = 1..1278</a>

%e n = 948, p = 898691 = prime(71194), q = 898717 = prime(71195);

%e n = 1134, p = 1285943 = prime(99033), q = 1285969 = prime(99034).

%p with(numtheory): A248785:=n->`if`(isprime(n^2-13) and isprime(n^2+13) and pi(n^2+13) = pi(n^2-13)+1,n,NULL): seq(A248785(n), n=1..2*10^4); # _Wesley Ivan Hurt_, Oct 13 2014

%t Select[Range[17000],PrimeQ[#^2-13]&&NextPrime[#^2-13]==#^2+13&] (* _Harvey P. Dale_, Aug 14 2020 *)

%o (PARI) isok(n) = isprime(p=n^2-13) && isprime(q=n^2+13) && (q==nextprime(p+1)); \\ _Michel Marcus_, Oct 14 2014

%Y Subsequence of A177833 and of A075190.

%Y E.g., a(1) = 948 = A075190(103) = A177833(15).

%K nonn

%O 1,1

%A _Zak Seidov_, Oct 13 2014

%E More terms from _Michel Marcus_, Oct 14 2014