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 A014935 #22 May 22 2025 01:02:46 %S A014935 1,37,1009,24337,549217,11886625,249972193,5147732449,104327377633, %T A014935 2087920281313,41363059774177,812583980724961,15851391939265249, %U A014935 307372900058661601,5929573413789876961,113875823277429211873,2178347851919531492065,41524755927216069067489,789106509357850283000545 %N A014935 a(1)=1, a(n) = n*18^(n-1) + a(n-1). %H A014935 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (37,-360,324). %F A014935 G.f.: x/((1 - x)*(1 - 18*x)^2). - _Stefano Spezia_, Mar 11 2020 %F A014935 From _Elmo R. Oliveira_, May 21 2025: (Start) %F A014935 E.g.f.: exp(x)*(1 + exp(17*x)*(306*x - 1))/289. %F A014935 a(n) = (18^n*(17*n - 1) + 1)/289. %F A014935 a(n) = 36*a(n-1) - 324*a(n-2) + 1 for n > 2. %F A014935 a(n) = 37*a(n-1) - 360*a(n-2) + 324*a(n-3) for n > 3. (End) %o A014935 (PARI) a(n) = (1+18^n*(17*n-1))/289; \\ _Jinyuan Wang_, Mar 11 2020 %o A014935 (PARI) Vec(-x/((x-1)*(18*x-1)^2) + O(x^20)) \\ _Elmo R. Oliveira_, May 21 2025 %K A014935 nonn,easy %O A014935 1,2 %A A014935 _Olivier Gérard_ %E A014935 More terms from _Elmo R. Oliveira_, May 21 2025