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 A200408 #24 Mar 12 2024 12:54:56
%S A200408 1,1,16,41,121,316,841,2201,5776,15121,39601,103676,271441,710641,
%T A200408 1860496,4870841,12752041,33385276,87403801,228826121,599074576,
%U A200408 1568397601,4106118241,10749957116,28143753121,73681302241,192900153616,505019158601,1322157322201
%N A200408 a(n) = -4 + 5*Fibonacci(n+1)^2.
%C A200408 a(1) and a(2n) are perfect squares.
%H A200408 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (3,0,-3,1).
%F A200408 a(n) = 3*a(n-1)-3*a(n-3)+a(n-4). G.f.: 1-x*(x^3-7*x^2+13*x+1) / ((x-1)*(x+1)*(x^2-3*x+1)). - _Colin Barker_, Sep 01 2013
%F A200408 a(n) = A005248(n+1) - A010696(n). - _R. J. Mathar_, Jan 18 2021
%t A200408 Table[-4 + 5*Fibonacci[n]^2, {n, 2, 31}] (* _Alonso del Arte_, Nov 17 2011 *)
%o A200408 (PARI) Vec(-x*(x^3-7*x^2+13*x+1)/((x-1)*(x+1)*(x^2-3*x+1)) + O(x^100)) \\ _Colin Barker_, Sep 01 2013
%Y A200408 Cf. A005248.
%K A200408 nonn,easy
%O A200408 0,3
%A A200408 _Artur Jasinski_, Nov 17 2011
%E A200408 a(0)=1 prepended by _Alois P. Heinz_, Mar 11 2024