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 A004174 #26 Feb 16 2025 08:32:28
%S A004174 1,-1,2,0,-4,4,2,0,-12,8,0,16,0,-32,16,-16,0,80,0,-80,32,0,-192,0,320,
%T A004174 0,-192,64,272,0,-1344,0,1120,0,-448,128,0,4352,0,-7168,0,3584,0,
%U A004174 -1024,256,-7936,0,39168,0,-32256,0,10752,0,-2304,512,0,-158720,0
%N A004174 Triangle of coefficients of Euler polynomials 2^n*E_n(x) (exponents in increasing order).
%D A004174 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 A004174 T. D. Noe, <a href="/A004174/b004174.txt">Rows n = 0..50 of triangle, flattened</a>
%H A004174 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].
%H A004174 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/EulerPolynomial.html">Euler Polynomial</a>.
%t A004174 Flatten[ Table[ CoefficientList[ 2^n*EulerE[n, x], x], {n, 0, 10}]] (* _Jean-François Alcover_, Jul 21 2011 *)
%Y A004174 Cf. A099932.
%K A004174 sign,tabl,nice
%O A004174 0,3
%A A004174 _N. J. A. Sloane_