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 A325675 #9 Feb 20 2022 08:19:00
%S A325675 -3,0,0,0,0,1,-6,21,-56,126,-252,463,-804,1365,-2366,4368,-8736,18565,
%T A325675 -40410,87381,-184604,379050,-758100,1486675,-2884776,5592405,
%U A325675 -10919090,21572460,-43144920,87087001,-176565486,357913941,-723002336,1453179126,-2906358251
%N A325675 First term of n-th difference sequence of (floor(k*r)), r = -sqrt(8), k >= 0.
%H A325675 Clark Kimberling, <a href="/A325675/b325675.txt">Table of n, a(n) for n = 1..200</a>
%t A325675 Table[First[Differences[Table[Floor[-Sqrt[8]*n], {n, 0, 30}], n]], {n, 0, 50}]
%Y A325675 Cf. A022842, A325664, A325674.
%K A325675 easy,sign
%O A325675 1,1
%A A325675 _Clark Kimberling_, May 15 2019