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 A228910 #50 Sep 08 2022 08:46:05 %S A228910 0,0,0,0,0,0,0,5040,181440,3780000,59875200,801496080,9574044480, %T A228910 105398092800,1091804313600,10794490827120,102896614941120, %U A228910 952741767650400,8617145057539200,76461500619902160,667855517349303360,5757691363157764800,49099453300298016000,414884142077935345200 %N A228910 a(n) = 8^n - 7*7^n + 21*6^n - 35*5^n + 35*4^n - 21*3^n + 7*2^n - 1. %C A228910 Calculates the eighth column of coefficients with respect to the derivatives, d^n/dx^n(y), of the logistic equation when written as y=1/[1+exp(-x)]. %H A228910 Seiichi Manyama, <a href="/A228910/b228910.txt">Table of n, a(n) for n = 0..1107</a> %H A228910 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (36,-546,4536,-22449,67284,-118124,109584,-40320). %F A228910 a(n) = 5040 * S2(n+1,8), n>=0. %F A228910 G.f.: 5040*x^7 / ((x-1)*(2*x-1)*(3*x-1)*(4*x-1)*(5*x-1)*(6*x-1)*(7*x-1)*(8*x-1)). - _Colin Barker_, Sep 20 2013 %F A228910 E.g.f.: Sum_{k=1..8} (-1)^(8-k)*binomial(8-1,k-1)*exp(k*x). - _Wolfdieter Lang_, May 03 2017 %t A228910 Derivative[0][y][x] = y[x]; Derivative[1][y][x] = y[x]*(1 - y[x]); Derivative[n_][y][x] := Derivative[n][y][x] = D[Derivative[n - 1][y][x], x]; row[n_] := CoefficientList[ Derivative[n][y][x], y[x]] // Rest; Join[{0, 0, 0, 0, 0, 0, 0}, Table[ -row[n], {n, 7, 23}] [[All, 8]]] (* _Jean-François Alcover_, Dec 16 2014 *) %t A228910 Table[7!*StirlingS2[n + 1, 8], {n, 0, 20}] (* _Vaclav Kotesovec_, Dec 16 2014 *) %t A228910 Table[8^n - 7*7^n + 21*6^n - 35*5^n + 35*4^n - 21*3^n + 7*2^n - 1, {n, 0, 20}] (* _Vaclav Kotesovec_, Dec 16 2014 *) %t A228910 CoefficientList[Series[5040*x^7 / ((x-1)*(2*x-1)*(3*x-1)*(4*x-1)*(5*x-1)*(6*x-1)*(7*x-1)*(8*x-1)), {x, 0, 20}], x] (* _Vaclav Kotesovec_, Dec 16 2014 after _Colin Barker_ *) %o A228910 (PARI) a(n)=8^(n)-7*7^(n)+21*6^(n)-35*5^(n)+35*4^(n)-21*3^(n)+7*2^(n)-1. %o A228910 (PARI) for(n=0,30, print1(5040*stirling(n+1,8,2), ", ")) \\ _G. C. Greubel_, Nov 19 2017 %o A228910 (Magma) [8^(n)-7*7^(n)+21*6^(n)-35*5^(n)+35*4^(n)-21*3^(n)+7*2^(n)-1: n in [0..30]]; // _G. C. Greubel_, Nov 19 2017 %Y A228910 Cf. A008277, A049434. %Y A228910 The eighth column of results of A163626. %Y A228910 Cf. A000225, A028243, A028244, A028245, A032180, A228909. %K A228910 nonn,easy %O A228910 0,8 %A A228910 _Richard V. Scholtz, III_, Sep 07 2013 %E A228910 Offset corrected by _Vaclav Kotesovec_, Dec 16 2014