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 A156636 #27 Dec 08 2024 11:06:34
%S A156636 1820,6214,10608,15002,19396,23790,28184,32578,36972,41366,45760,
%T A156636 50154,54548,58942,63336,67730,72124,76518,80912,85306,89700,94094,
%U A156636 98488,102882,107276,111670,116064,120458,124852,129246,133640,138034,142428,146822,151216,155610
%N A156636 a(n) = 4394*n + 1820.
%C A156636 The identity (57122*n^2 + 47320*n + 9801)^2 - (169*n^2 + 140*n + 29)*(4394*n + 1820)^2 = 1 can be written as A156735(n)^2 - A156640(n)*a(n)^2 = 1.
%H A156636 Vincenzo Librandi, <a href="/A156636/b156636.txt">Table of n, a(n) for n = 0..10000</a>
%H A156636 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1).
%F A156636 G.f.: 26*(70+99*x)/(x-1)^2. - _R. J. Mathar_, Jan 05 2011
%F A156636 a(n) = 2*a(n-1) - a(n-2).
%F A156636 E.g.f.: 26*exp(x)*(70 + 169*x). - _Elmo R. Oliveira_, Dec 08 2024
%t A156636 LinearRecurrence[{2,-1},{1820,6214},50]
%o A156636 (Magma) I:=[1820, 6214]; [n le 2 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..50]];
%o A156636 (PARI) a(n)=4394*n+1820 \\ _Charles R Greathouse IV_, Dec 23 2011
%Y A156636 Cf. A156640, A156718, A156735.
%K A156636 nonn,easy
%O A156636 0,1
%A A156636 _Vincenzo Librandi_, Feb 15 2009
%E A156636 Offset corrected by _R. J. Mathar_, Jan 05 2011