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 A187361 #26 Oct 18 2024 23:21:46
%S A187361 1,12,169,2378,33461,470832,6625109,93222358,1311738121,18457556052,
%T A187361 259717522849,3654502875938,51422757785981,723573111879672,
%U A187361 10181446324101389,143263821649299118,2015874949414289041,28365513113449345692,399133058537705128729,5616228332641321147898
%N A187361 Pell trisection: Pell(3*n+1), n >= 0.
%C A187361 For the general computation of the o.g.f.s for the trisection of a sequence, given by its real o.g.f., see a _Wolfdieter Lang_ comment under A187357.
%H A187361 Colin Barker, <a href="/A187361/b187361.txt">Table of n, a(n) for n = 0..850</a>
%H A187361 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (14,1).
%F A187361 a(n) = Pell(3*n+1), n >= 0, with Pell(n):=A000129(n).
%F A187361 O.g.f.: (1-2*x)/(1-14*x-x^2).
%F A187361 a(n) = 14*a(n-1) + a(n-2), a(0)= 1, a(1)=12.
%F A187361 a(n) = (((7-5*sqrt(2))^n*(-1+sqrt(2))+(1+sqrt(2))*(7+5*sqrt(2))^n))/(2*sqrt(2)). - _Colin Barker_, Jan 25 2016
%t A187361 Table[Fibonacci[3n + 1, 2], {n, 0, 20}] (* _Vladimir Reshetnikov_, Sep 16 2016 *)
%t A187361 LinearRecurrence[{14,1},{1,12},20] (* _Harvey P. Dale_, Jul 06 2023 *)
%o A187361 (PARI) Vec((1-2*x)/(1-14*x-x^2) + O(x^20)) \\ _Colin Barker_, Jan 25 2016
%Y A187361 Cf. A142588 (Pell(3*n)), A187362 (Pell(3*n+2)).
%K A187361 nonn,easy
%O A187361 0,2
%A A187361 _Wolfdieter Lang_, Mar 09 2011