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 A199716 #29 Mar 20 2023 12:34:17
%S A199716 16,20,21,35,37,50,51,54,55,61,66,68,76,79,81,83,86,89,90,105,112,115,
%T A199716 118,121,125,128,130,131,134,141,142,145,146,149,150,151,153,156,160,
%U A199716 161,165,168,180,181,186,190,191,195,200,202,208,211,212,219,223
%N A199716 Numbers k such that 6k-5 and 6k-1 are both composite.
%t A199716 Select[Range[223], ! PrimeQ[6#-5] && ! PrimeQ[6#-1] &] (* _T. D. Noe_, Nov 09 2011 *)
%t A199716 Select[Range[250],AllTrue[6#+{-5,-1},CompositeQ]&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Oct 11 2018 *)
%o A199716 (Magma) [ n: n in [1..223] | not IsPrime(6*n-5) and not IsPrime(6*n-1) ]; // _Bruno Berselli_, Nov 09 2011
%o A199716 (PARI) for(n=1,1e3,if(!isprime(6*n-5)&&!isprime(6*n-1),print1(n", "))) \\ _Charles R Greathouse IV_, Nov 10 2011
%Y A199716 Cf. A186243.
%K A199716 nonn,easy
%O A199716 1,1
%A A199716 _Eleonora Echeverri-Toro_, Nov 09 2011