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 A325739 #5 Jun 03 2019 19:47:59
%S A325739 3,0,0,0,0,0,0,1,-8,36,-120,330,-792,1716,-3431,6420,-11320,18768,
%T A325739 -28764,38760,-38760,1,149204,-571780,1613128,-3964050,8934120,
%U A325739 -18874260,37748521,-71705864,129080160,-218205280,339081224,-459957168,459957168,1,-1749692736
%N A325739 First term of n-th difference sequence of (floor(Pi*k)), k >= 0.
%H A325739 Clark Kimberling, <a href="/A325739/b325739.txt">Table of n, a(n) for n = 1..200</a>
%t A325739 Table[First[Differences[Table[Floor[Pi*n], {n, 0, 50}], n]], {n, 1, 50}]
%Y A325739 Cf. A022844, A325664.
%K A325739 easy,sign
%O A325739 1,1
%A A325739 _Clark Kimberling_, May 23 2019