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 A325669 #12 Feb 20 2022 08:15:33
%S A325669 -3,1,-1,1,-2,6,-16,36,-72,136,-256,496,-992,2016,-4096,8256,-16512,
%T A325669 32896,-65536,130816,-261631,523754,-1048323,2096152,-4183701,8324850,
%U A325669 -16480855,32363020,-62784775,119759850,-223346545,404492000,-705032195,1166803110
%N A325669 First term of n-th difference sequence of (floor(k*r)), r = -sqrt(5), k >= 0.
%H A325669 Clark Kimberling, <a href="/A325669/b325669.txt">Table of n, a(n) for n = 1..200</a>
%t A325669 Table[First[Differences[Table[Floor[-Sqrt[5]*n], {n, 0, 50}], n]], {n, 1, 50}]
%Y A325669 Cf. A325664, A325668.
%K A325669 easy,sign
%O A325669 1,1
%A A325669 _Clark Kimberling_, May 13 2019