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 A052245 #28 Jan 16 2022 08:24:28 %S A052245 0,10,210,3210,43210,543210,6543210,76543210,876543210,9876543210, %T A052245 109876543210,1209876543210,13209876543210,143209876543210, %U A052245 1543209876543210,16543209876543210,176543209876543210,1876543209876543210,19876543209876543210,209876543209876543210 %N A052245 Expansion of 10*x / ((1 - x) * (1 - 10*x)^2) in powers of x. %C A052245 This is not the same as A052246. They differ at a(11) and beyond. - _Michael Somos_, Sep 14 2014 %H A052245 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (21,-120,100). %F A052245 a(n) = n*10^n+a(n-1), a(0) = 0; a(n) = ((9n-1)*10^n + 1) * 10 / 81; a(n) = A014925(n)*10. %F A052245 a(n) = 21*a(n-1)-120*a(n-2)+100*a(n-3). - _Colin Barker_, Sep 13 2014 %F A052245 G.f.: -10*x / ((x-1)*(10*x-1)^2). - _Colin Barker_, Sep 13 2014 %p A052245 seq(sum(x*10^x,x=0..a),a=0..100); # _Jorge Coveiro_, Dec 22 2004 %p A052245 a:=n->sum((10^(n-j)*(n-j)),j=0..n): seq(a(n), n=0..16); # _Zerinvary Lajos_, Jun 05 2008 %o A052245 (PARI) concat(0, Vec(-10*x/((x-1)*(10*x-1)^2) + O(x^100))) \\ _Colin Barker_, Sep 13 2014 %Y A052245 Cf. A014925, A052246. %K A052245 easy,nonn %O A052245 0,2 %A A052245 _Henry Bottomley_, Feb 01 2000 %E A052245 More terms from _Colin Barker_, Sep 13 2014