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 A004175 #18 Jan 31 2022 01:30:04
%S A004175 1,2,-1,4,-4,0,8,-12,0,2,16,-32,0,16,0,32,-80,0,80,0,-16,64,-192,0,
%T A004175 320,0,-192,0,128,-448,0,1120,0,-1344,0,272,256,-1024,0,3584,0,-7168,
%U A004175 0,4352,0,512,-2304,0,10752,0,-32256,0,39168,0,-7936,1024
%N A004175 Triangle of coefficients of Euler polynomials 2^n*E_n(x) (exponents in decreasing order).
%D A004175 M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 809.
%H A004175 Vincenzo Librandi, <a href="/A004175/b004175.txt">Table of n, a(n) for n = 0..1000</a>
%H A004175 M. Abramowitz and I. A. Stegun, eds., <a href="http://www.convertit.com/Go/ConvertIt/Reference/AMS55.ASP">Handbook of Mathematical Functions</a>, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].
%t A004175 Flatten[Table[2^n*Reverse@CoefficientList[EulerE[n,x], x],{n,0,10}]][[1;;56]] (* _Jean-François Alcover_, Apr 29 2011 *)
%K A004175 sign,tabl,nice,easy
%O A004175 0,2
%A A004175 _N. J. A. Sloane_