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 A199110 #34 Apr 02 2025 19:06:13 %S A199110 8,22,64,190,568,1702,5104,15310,45928,137782,413344,1240030,3720088, %T A199110 11160262,33480784,100442350,301327048,903981142,2711943424, %U A199110 8135830270,24407490808,73222472422,219667417264,659002251790,1977006755368,5931020266102,17793060798304,53379182394910 %N A199110 a(n) = 7*3^n + 1. %H A199110 Vincenzo Librandi, <a href="/A199110/b199110.txt">Table of n, a(n) for n = 0..1000</a> %H A199110 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (4,-3). %F A199110 a(n) = 3*a(n-1) - 2 = A005032(n) + 1. %F A199110 a(n) = 4*a(n-1) - 3*a(n-2). %F A199110 From _Bruno Berselli_, Nov 03 2011: (Start) %F A199110 G.f.: 2*(4-5*x)/((1-x)*(1-3*x)). %F A199110 a(n) = 2*A199109(n). (End) %F A199110 E.g.f.: exp(x)*(1 + 7*exp(2*x)). - _Elmo R. Oliveira_, Apr 02 2025 %t A199110 7*3^Range[0, 30] + 1 (* _Paolo Xausa_, Jan 28 2025 *) %o A199110 (Magma) [7*3^n+1: n in [0..30]]; %o A199110 (Python) %o A199110 def a(n): return 7*3**n + 1 %o A199110 print([a(n) for n in range(26)]) # _Michael S. Branicky_, Aug 22 2021 %Y A199110 Cf. A005032, A199109. %K A199110 nonn,easy %O A199110 0,1 %A A199110 _Vincenzo Librandi_, Nov 03 2011