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 A089965 #6 Dec 13 2018 19:06:30 %S A089965 2,4,12,36,60,72,156,192,276,312,396,420,456,540,612,660,672,732,756, %T A089965 876,996,1092,1152,1200,1212,1236,1320,1380,1452,1620,1656,1752,1872, %U A089965 1932,1992,2016,2136,2340,2472,2556,2592,2796,2856,2916,3060,3216,3252 %N A089965 Both n + 1 and n/2 + 1 are primes. %F A089965 a(n) = A005383(n)-1. - _Robert Israel_, Dec 13 2018 %t A089965 Select[Range[5*10^3], PrimeQ[ # + 1] && PrimeQ[ #/2 + 1] &] %Y A089965 Cf. A005383. %K A089965 nonn %O A089965 1,1 %A A089965 _Joseph L. Pe_, Jan 18 2004