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 A325670 #6 Feb 20 2022 08:16:28
%S A325670 2,0,1,-3,7,-15,31,-63,127,-255,510,-1011,1968,-3717,6720,-11439,
%T A325670 17874,-24309,24309,0,-92358,352485,-997569,2485242,-5754024,12680955,
%U A325670 -26924184,55410642,-110821283,215426355,-406270425,740354804,-1294617072,2145852303
%N A325670 First term of n-th difference sequence of (floor(k*r)), r = sqrt(6), k >= 0.
%H A325670 Clark Kimberling, <a href="/A325670/b325670.txt">Table of n, a(n) for n = 1..200</a>
%t A325670 Table[First[Differences[Table[Floor[Sqrt[6]*n], {n, 0, z}], n]], {n, 0, 50}]
%Y A325670 Cf. A022840, A325664, A325671.
%K A325670 easy,sign
%O A325670 1,1
%A A325670 _Clark Kimberling_, May 13 2019