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 A216302 #21 Feb 14 2025 19:23:59
%S A216302 4,31,46,64,88,109,130,367,400,493,523,550,823,829,886,946,1033,1117,
%T A216302 1369,1390,1408,1432,1825,1999,2161,2329,2356,2374,2503,2626,2668,
%U A216302 2671,2794,2902,3049,3139,3151,3154,3232,3253,3421,3553,3559,3601,3799,3904
%N A216302 Numbers k such that 10k+9 is composite but 10k+1, 10k+3, 10k+7 are all prime.
%H A216302 V. Raman, <a href="/A216302/b216302.txt">Table of n, a(n) for n = 1..10000</a>
%F A216302 a(n) >> n log^3 n. - _Charles R Greathouse IV_, Sep 07 2012
%t A216302 t = {}; Do[ps = Select[Range[10*n, 10*n + 9], PrimeQ]; If[ps == {10*n + 1, 10*n + 3, 10*n + 7}, AppendTo[t, n]], {n, 0, 4903}]; t (* _T. D. Noe_, Sep 03 2012 *)
%t A216302 Select[Range[4000],!PrimeQ[10#+9]&&And@@PrimeQ[10#+{1,3,7}]&] (* _Harvey P. Dale_, May 23 2014 *)
%t A216302 Select[Range[4000],Boole[PrimeQ[10 #+{1,3,7,9}]]=={1,1,1,0}&] (* _Harvey P. Dale_, Feb 14 2025 *)
%Y A216302 Cf. A032352, A007811, A078494.
%K A216302 nonn
%O A216302 1,1
%A A216302 _V. Raman_, Sep 03 2012