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 A082651 #15 Mar 18 2024 09:51:50
%S A082651 1,7,25,127,449,2279,8057,40895,144577,733831,2594329,13168063,
%T A082651 46553345,236291303,835365881,4240075391,14990032513,76085065735,
%U A082651 268985219353,1365291107839,4826743915841,24499154875367,86612405265785,439619496648767,1554196550868289
%N A082651 Positive integer values of n such that 5n^2+11 is a square.
%C A082651 The corresponding sequence for which 5n^2+4 is a square is A001906 (a bisection of the Fibonacci sequence).
%H A082651 Colin Barker, <a href="/A082651/b082651.txt">Table of n, a(n) for n = 1..1000</a>
%H A082651 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (0,18,0,-1).
%F A082651 a(n) = 18*a(n-2) - a(n-4).
%F A082651 G.f.: x*(1+7*x+7*x^2+x^3)/(1-18*x^2+x^4). - _Colin Barker_, Jun 14 2012
%e A082651 25 is a term of the sequence since 5*25^2 + 11 = 56^2.
%t A082651 LinearRecurrence[{0, 18, 0, -1}, {1, 7, 25, 127}, 50] (* _Paolo Xausa_, Mar 18 2024 *)
%o A082651 (PARI) Vec(x*(1+7*x+7*x^2+x^3)/(1-18*x^2+x^4) + O(x^100)) \\ _Colin Barker_, Nov 06 2014
%Y A082651 Cf. A001906, A080806.
%K A082651 nonn,easy
%O A082651 1,2
%A A082651 _John W. Layman_, May 16 2003
%E A082651 More terms from _Colin Barker_, Nov 06 2014