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 A141684 #13 Dec 29 2023 10:28:28 %S A141684 1,-1,2,0,-1,1,1,0,-6,4,0,1,0,-2,1,-4,0,20,0,-20,8,0,-3,0,5,0,-3,1,34, %T A141684 0,-168,0,140,0,-56,16,0,17,0,-28,0,14,0,-4,1,-496,0,2448,0,-2016,0, %U A141684 672,0,-144,32,0,-155,0,255,0,-126,0,30,0,-5,1 %N A141684 Triangle read by rows formed from Euler polynomials: p(x,n) = if(n mod 2 = 1, 2^(1 + ((n - 1)/2))*EulerE(n, x), EulerE(n, x)); t(n,m) = Coefficients(p(x,n)). %C A141684 Row sums are {1, 1, 0, -1, 0, 4, 0, -34, 0, 496, 0, ...}. %H A141684 G. C. Greubel, <a href="/A141684/b141684.txt">Rows n=1..100 of triangle, flattened</a> %e A141684 { 1}, %e A141684 { -1, 2}, %e A141684 { 0, -1, 1}, %e A141684 { 1, 0, -6, 4}, %e A141684 { 0, 1, 0, -2, 1}, %e A141684 { -4, 0, 20, 0, -20, 8}, %e A141684 { 0, -3, 0, 5, 0, -3, 1}, %e A141684 { 34, 0, -168, 0, 140, 0, -56, 16}, %e A141684 { 0, 17, 0, -28, 0, 14, 0, -4, 1}, %e A141684 {-496, 0, 2448, 0, -2016, 0, 672, 0, -144, 32}, %e A141684 { 0, -155, 0, 255, 0, -126, 0, 30, 0, -5, 1} %t A141684 T[x_, n_] := If[Mod[n, 2] == 1, 2^(1 + ((n - 1)/2))*EulerE[n, x], EulerE[n, x]]; Table[Expand[T[x, n]], {n, 0, 10}]; Table[CoefficientList[T[x, n], x], {n, 0, 10}]; Flatten[%] %Y A141684 Cf. A060083, A004172, etc. %K A141684 tabl,sign %O A141684 1,3 %A A141684 _Roger L. Bagula_ and _Gary W. Adamson_, Sep 08 2008 %E A141684 Edited by _N. J. A. Sloane_, Jan 06 2009