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 A199111 #28 May 07 2025 11:54:53 %S A199111 9,25,73,217,649,1945,5833,17497,52489,157465,472393,1417177,4251529, %T A199111 12754585,38263753,114791257,344373769,1033121305,3099363913, %U A199111 9298091737,27894275209,83682825625,251048476873,753145430617,2259436291849,6778308875545,20334926626633,61004779879897 %N A199111 a(n) = 8*3^n + 1. %H A199111 Vincenzo Librandi, <a href="/A199111/b199111.txt">Table of n, a(n) for n = 0..1000</a> %H A199111 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (4,-3). %F A199111 a(n) = 3*a(n-1) - 2. %F A199111 a(n) = 4*a(n-1) - 3*a(n-2). %F A199111 G.f.: (9-11*x)/((1-x)*(1-3*x)). - _Bruno Berselli_, Nov 03 2011 %F A199111 a(n) = 8*A000244(n) + 1 = A005051(n) + 1. - _Omar E. Pol_, Nov 18 2011 %F A199111 From _Elmo R. Oliveira_, May 07 2025: (Start) %F A199111 E.g.f.: exp(x)*(8*exp(2*x) + 1). %F A199111 a(n) = A198644(n) + 2. (End) %o A199111 (Magma) [8*3^n+1: n in [0..30]]; %Y A199111 Cf. A000244, A005051, A160173. - _Omar E. Pol_, Nov 18 2011 %Y A199111 Cf. A198644. %K A199111 nonn,easy %O A199111 0,1 %A A199111 _Vincenzo Librandi_, Nov 03 2011