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 A263391 #15 Jan 10 2018 03:24:16
%S A263391 12151397,31210219,45181667,56191673,66887071,68468753,69169397,
%T A263391 71307347,114921271,122311103,133228283,152252267,154337567,182479909,
%U A263391 185282537,192413177,210465533,220192013,226521259,235663343,236281883,253282909,275248343,282777829
%N A263391 Sierpiński numbers that have at least two covering sets.
%H A263391 Wikipedia, <a href="http://en.wikipedia.org/wiki/Sierpinski_number">Sierpinski number</a>
%e A263391 For every k >= 1, 12151397*2^k + 1 has a divisor in the set {3, 5, 7, 13, 19, 37, 73} and also in the set {3, 5, 7, 13, 19, 73, 109}. 12151397 is therefore in the sequence.
%Y A263391 Cf. A076336, A263392.
%K A263391 nonn
%O A263391 1,1
%A A263391 _Arkadiusz Wesolowski_, Oct 16 2015
%E A263391 2 terms inserted by _Arkadiusz Wesolowski_, Aug 28 2016
%E A263391 More terms from _Arkadiusz Wesolowski_, Jan 09 2018