This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A154775 #15 Dec 25 2019 04:49:59 %S A154775 2,4,5,42,46,49,59,82,84,100,119,128,137,182,185,187,192,233,264,301, %T A154775 303,340,376,390,395,422,438,446,471,472,494,518,527,570,598,609,611, %U A154775 633,667,688,714,716,726,728,733,744,831,837,865,875,896,926,940,948 %N A154775 Numbers k such that 13*(6*k)^2 is the average of a twin prime pair. %C A154775 Inspired by _Zak Seidov_'s post to the SeqFan list, cf. link: This yields A154675 as 468 a(n)^2. Indeed, if N/13 is a square, then N=13 k^2 and this can't be the average of a twin prime pair unless k=6m. %H A154775 Amiram Eldar, <a href="/A154775/b154775.txt">Table of n, a(n) for n = 1..10000</a> %H A154775 Zak Seidov, <a href="http://zak08.livejournal.com/4070.html">"A154676"</a>, Jan 15 2009 %F A154775 a(n) = sqrt(A154675(n)/468). %t A154775 okQ[n_]:=Module[{av=468n^2},PrimeQ[av-1]&&PrimeQ[av+1]]; Select[Range[1000],okQ] (* _Harvey P. Dale_, Jan 21 2011 *) %o A154775 (PARI) for(i=1,999, isprime(468*i^2+1) & isprime(468*i^2-1) & print1(i",")) %Y A154775 Cf. A014574, A037073, A154331, A154772, A154773, A154774, A154675. %K A154775 nonn %O A154775 1,1 %A A154775 _M. F. Hasler_, Jan 15 2009