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 A157782 #6 Mar 19 2014 05:46:08
%S A157782 1,1,12,4,240,16,1344,64,3840,256,33792,1024,5591040,4096,49152,16384,
%T A157782 16711680,65536,104595456,262144,173015040,1048576,289406976,4194304,
%U A157782 22900899840,16777216,201326592,67108864,116769423360,268435456
%N A157782 Denominator of Bernoulli(n, -1/2).
%H A157782 Vincenzo Librandi, <a href="/A157782/b157782.txt">Table of n, a(n) for n = 0..250</a>
%t A157782 Table[Denominator[BernoulliB[n, -1/2]], {n, 0, 50}] (* _Vincenzo Librandi_, Mar 19 2014 *)
%Y A157782 For numerators see A157781.
%K A157782 nonn,frac
%O A157782 0,3
%A A157782 _N. J. A. Sloane_, Nov 08 2009