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 A177096 #15 May 02 2025 16:05:00 %S A177096 40,490,4990,49990,499990,4999990,49999990,499999990,4999999990, %T A177096 49999999990,499999999990,4999999999990,49999999999990, %U A177096 499999999999990,4999999999999990,49999999999999990,499999999999999990,4999999999999999990,49999999999999999990,499999999999999999990 %N A177096 a(n) = 5*(10^n - 2). %H A177096 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (11,-10). %F A177096 G.f.: 10*x*(4+5*x)/((10*x-1)*(x-1)). - _R. J. Mathar_, Jan 06 2011 %F A177096 From _Elmo R. Oliveira_, May 02 2025: (Start) %F A177096 E.g.f.: 5*(1 + exp(10*x) - 2*exp(x)). %F A177096 a(n) = 5*A099150(n) = 10*A198971(n-1). %F A177096 a(n) = 11*a(n-1) - 10*a(n-2) for n > 2. (End) %o A177096 (PARI) Vec(10*x*(4+5*x)/(10*x^2-11*x+1) + O(x^21)) \\ _Elmo R. Oliveira_, May 02 2025 %Y A177096 Cf. A099150, A198971. %K A177096 nonn,easy %O A177096 1,1 %A A177096 _Vincenzo Librandi_ %E A177096 More terms from _Elmo R. Oliveira_, May 02 2025