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 A142249 #31 Feb 16 2025 08:33:08 %S A142249 -1,-1,1,-1,2,-1,3,3,-1,4,19,4,-1,5,80,65,5,-1,6,286,566,181,6,-1,7, %T A142249 945,3710,2905,455,7,-1,8,2997,20756,31781,12636,1079,8,-1,9,9294, %U A142249 105299,278304,218559,49754,2469,9 %N A142249 Triangle read by rows, a generalization of the Eulerian numbers based on Nielsen's generalized polylogarithm (case m = 2). %H A142249 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/NielsenGeneralizedPolylogarithm.html">Nielsen Generalized Polylogarithm</a>. %F A142249 Let p(n, m) = (m - 1)!*(1 - x)^n*PolyLog(-n, m, x)/x and P(n) the polynomial given by the expansion of p(n, m=2) after replacing log(1 - x) by 1. T(n, k) is the k-th coefficient of P(n). Using instead p(n, m=1) gives the Eulerian numbers A008292. %e A142249 Triangle starts: %e A142249 {-1} %e A142249 {-1, 1} %e A142249 {-1, 2} %e A142249 {-1, 3, 3} %e A142249 {-1, 4, 19, 4} %e A142249 {-1, 5, 80, 65, 5} %e A142249 {-1, 6, 286, 566, 181, 6} %e A142249 {-1, 7, 945, 3710, 2905, 455, 7} %e A142249 {-1, 8, 2997, 20756, 31781, 12636, 1079, 8} %e A142249 {-1, 9, 9294, 105299, 278304, 218559, 49754, 2469, 9} %e A142249 ... %e A142249 For example with n = 4 we have p(n, x ) = (2-1)! * (1 - x)^n * PolyLog(-n, 2, x)/x %e A142249 = x*(7 + 4*x) - (1 + 4*x + x^2)*log(1-x). Replacing log(1-x) by 1 reduces this to x*(7 + 4*x) - (1 + 4*x + x^2) = 3*x^2 + 3*x - 1 with coefficients [-1, 3, 3]. %t A142249 npl[n_, m_] := (m-1)! (1 - x)^n PolyLog[-n, m, x]/x; %t A142249 A142249Row[n_] := CoefficientList[FunctionExpand[npl[n, 2]], x] /. Log[1-x] -> 1; %t A142249 Table[A142249Row[n], {n, 1, 10}] // Flatten %t A142249 (* Some older versions of Mathematica might use: *) %t A142249 Flatten[Table[CoefficientList[Simplify[(1-x)^n * PolyLog[-n, 2, x] / (x*Log[1-x])], x]/.x->1-E, {n, 1, 15}]] (* _Vaclav Kotesovec_, Oct 12 2017 *) %Y A142249 Row sums are A081047. %Y A142249 A008292 (m=1), A142249 (m=2), A293298 (m=3 with an additional first column). %Y A142249 Cf. A293561 (column 3), A293562 (column 4). %K A142249 sign,tabl %O A142249 1,5 %A A142249 _Roger L. Bagula_ and _Gary W. Adamson_, Sep 18 2008 %E A142249 Edited by _Peter Luschny_, Oct 11 2017