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 A226694 #15 Feb 12 2024 10:18:13
%S A226694 1,4099,16797701,68836974599,282093905109001,1156020754299711499,
%T A226694 4737372769026312613901,19413752451449074792054799,
%U A226694 79557552808665539471527952401,326026831996158929305246756884499,1336057877962706483627361738184724501
%N A226694 Pell equation solutions (32*a(n))^2 - 41*(5*b(n))^2 = -1 with b(n) := A226695(n), n>=0.
%H A226694 <a href="/index/Ch#Cheby">Index entries for sequences related to Chebyshev polynomials.</a>
%H A226694 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (4098,-1)
%F A226694 a(n) = S(n,4098)+ S(n-1,4098), n>=0, with the Chebyshev S-polynomials (A049310). 4098 = 17*241 is the smallest positive integer x solution of x^2 - 41*y^2 = +4 with y also positive.
%F A226694 O.g.f.: (1 + x)/(1 - 4098*x + x^2).
%F A226694 a(n) = 4098*a(n-1) - a(n-2), a(-1) = -1 , a(0) = 1.
%e A226694 Pell n=0: 32^2 - 41*5^2 = -1.
%e A226694 Pell n=1: (32*4099)^2 - 41*(5*4097)^2 = -1.
%t A226694 LinearRecurrence[{4098,-1},{1,4099},20] (* _Harvey P. Dale_, Sep 23 2017 *)
%Y A226694 Cf. A097314, A097315 (Pell -1 with D = 10), A226695.
%K A226694 nonn,easy
%O A226694 0,2
%A A226694 _Wolfdieter Lang_, Jun 20 2013