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 A097182 #13 Sep 08 2022 08:45:14 %S A097182 1,7,21,21,-63,-231,-15,1521,3073,-4319,-29631,-29631,143361,489345, %T A097182 -255,-3342591,-6684671,9454081,64553985,64553985,-311689215, %U A097182 -1064175615,-4095,7266627585,14533263361,-20553129983,-140345589759,-140345589759,677648531457,2313636773889 %N A097182 G.f. A(x) has the property that the first (n+1) terms of A(x)^(n+1) form the n-th row polynomial R_n(y) of triangle A097181 and satisfy R_n(1/2) = 8^n for all n>=0. %H A097182 G. C. Greubel, <a href="/A097182/b097182.txt">Table of n, a(n) for n = 0..1000</a> %F A097182 G.f.: A(x) = 16*x/(1-(1-2*x)^8). %e A097182 A(x) = 1 + 7*x + 21*x^2 + 21*x^3 - 63*x^4 - 231*x^5 - 15*x^6 +-... %e A097182 For n>=0, the first (n+1) coefficients of A(x)^(n+1) forms the %e A097182 n-th row polynomial R_n(y) of triangle A097181: %e A097182 A^1 = {1, _7, 21, 21, -63, -231, -15, 1521, ...} %e A097182 A^2 = {1, 14, _91, 336, 609, -462, -5469, -9516, ...} %e A097182 A^3 = {1, 21, 210, _1288, 5103, 11655, 2160, -85590, ...} %e A097182 A^4 = {1, 28, 378, 3220, _18907, 77280, 199860, 153000, ...} %e A097182 A^5 = {1, 35, 595, 6475, 49910, _283192, 1175190, 3282870, ...} %e A097182 A^6 = {1, 42, 861, 11396, 108402, 778596, _4296034, 17959968, ...} %e A097182 These row polynomials satisfy: R_n(1/2) = 8^n: %e A097182 8^1 = 1 + 14/2; %e A097182 8^2 = 1 + 21/2 + 210/2^2; %e A097182 8^3 = 1 + 28/2 + 378/2^2 + 3220/2^3; %e A097182 8^4 = 1 + 35/2 + 595/2^2 + 6475/2^3 + 49910/2^4. %p A097182 seq(coeff(series(16*x/(1-(1-2*x)^8), x, n+2), x, n), n = 0..30); # _G. C. Greubel_, Sep 17 2019 %t A097182 CoefficientList[Series[16*x/(1-(1-2*x)^8), {x,0,30}], x] (* _G. C. Greubel_, Sep 17 2019 *) %o A097182 (PARI) a(n)=polcoeff(16*x/(1-(1-2*x)^8)+x*O(x^n),n,x) %o A097182 (Magma) R<x>:=PowerSeriesRing(Rationals(), 30); Coefficients(R!( 16*x/(1-(1-2*x)^8) )); // _G. C. Greubel_, Sep 17 2019 %o A097182 (Sage) %o A097182 def A097194_list(prec): %o A097182 P.<x> = PowerSeriesRing(QQ, prec) %o A097182 return P(16*x/(1-(1-2*x)^8)).list() %o A097182 A097194_list(30) # _G. C. Greubel_, Sep 17 2019 %Y A097182 Cf. A097181, A097183, A097184, A097185. %K A097182 sign %O A097182 0,2 %A A097182 _Paul D. Hanna_, Aug 03 2004