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 A106630 #14 Sep 09 2021 03:00:16 %S A106630 7,8,12,13,17,20,24,25,28,29,32,39,42,45,52,53,58,59,63,64,67,72,75, %T A106630 79,83,87,88,93,100,102,114,115,125,126,127,131,139,140,144,154,159, %U A106630 160,173,180,190,195,219,223,232,234,240,248,253,265,278,279,284,296,299 %N A106630 Numbers k such that (prime(k)^2 - 1)/6 - prime(k) is prime. %H A106630 G. C. Greubel, <a href="/A106630/b106630.txt">Table of n, a(n) for n = 1..1000</a> %e A106630 (17^2 -1)/6 - 17 = 48 - 17 = 31 is prime, 17=prime(7), so 7 is a term. %t A106630 Select[Range[350], PrimeQ[(Prime[#]^2 -6*Prime[#] -1)/6] &] (* _G. C. Greubel_, Sep 08 2021 *) %o A106630 (PARI) is(n,p=prime(n))=isprime((p^2-1)/6-p) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A106630 Cf. A084922. %K A106630 nonn %O A106630 1,1 %A A106630 _Pierre CAMI_, May 11 2005 %E A106630 a(12) corrected by _R. J. Mathar_, Nov 13 2009