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 A164135 #28 Feb 26 2023 02:28:53
%S A164135 7,40,54,87,101,134,148,181,195,228,242,275,289,322,336,369,383,416,
%T A164135 430,463,477,510,524,557,571,604,618,651,665,698,712,745,759,792,806,
%U A164135 839,853,886,900,933,947,980,994,1027,1041,1074,1088,1121,1135,1168,1182
%N A164135 Numbers k such that k^2 == 2 (mod 47).
%C A164135 Numbers congruent to {7, 40} mod 47. - _Amiram Eldar_, Feb 26 2023
%H A164135 Vincenzo Librandi, <a href="/A164135/b164135.txt">Table of n, a(n) for n = 1..1000</a>
%H A164135 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (1,1,-1).
%F A164135 a(n) = a(n-1)+a(n-2)-a(n-3) for n>3.
%F A164135 a(n) = (47+19*(-1)^n+94*(n-1))/4.
%F A164135 G.f.: x*(7+33*x+7*x^2)/((1+x)*(x-1)^2). - _R. J. Mathar_, Aug 26 2009
%F A164135 Sum_{n>=1} (-1)^(n+1)/a(n) = cot(7*Pi/47)*Pi/47. - _Amiram Eldar_, Feb 26 2023
%p A164135 A164135:=n->(47+19*(-1)^n+94*(n-1))/4: seq(A164135(n), n=1..100); # _Wesley Ivan Hurt_, Mar 30 2017
%t A164135 Select[Range[1200], Mod[#^2, 47] == 2 &] (* _Vincenzo Librandi_, Apr 06 2013 *)
%t A164135 Select[Range[2000],PowerMod[#,2,47]==2&] (* or *) LinearRecurrence[ {1,1,-1},{7,40,54},60] (* _Harvey P. Dale_, Sep 29 2013 *)
%o A164135 (Magma) [(47+19*(-1)^n+94*(n-1))/4: n in [1..60]]; // _Vincenzo Librandi_, Apr 06 2013
%K A164135 nonn,easy
%O A164135 1,1
%A A164135 _Vincenzo Librandi_, Aug 11 2009
%E A164135 Edited by _R. J. Mathar_, Aug 26 2009