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 A032704 #16 Aug 30 2025 12:55:25
%S A032704 0,2,3,6,9,11,20,21,23,24,26,27,39,42,44,45,48,56,59,62,65,69,72,75,
%T A032704 80,83,86,87,93,95,101,105,108,113,114,116,120,122,123,128,134,135,
%U A032704 138,141,149,152,161,162,164,165,168,176,177,180,185,191,194,198,206
%N A032704 Numbers k such that k prefixed by '4' and followed by '1' is prime.
%H A032704 Harvey P. Dale, <a href="/A032704/b032704.txt">Table of n, a(n) for n = 1..1000</a>
%t A032704 Select[Range[0,250],PrimeQ[FromDigits[Join[{4},IntegerDigits[#],{1}]]]&] (* _Harvey P. Dale_, Aug 30 2025 *)
%Y A032704 Cf. A032702-A032733.
%K A032704 nonn,base,changed
%O A032704 1,2
%A A032704 _Patrick De Geest_, May 15 1998
%E A032704 Offset changed by _Andrew Howroyd_, Aug 11 2024