%I #4 Jun 09 2019 13:10:09
%S 3,0,0,1,-4,10,-20,35,-56,84,-119,154,-154,0,637,-2548,7448,-18767,
%T 42924,-91238,182476,-345401,618772,-1041348,1613129,-2184910,2184910,
%U 0,-8333871,31750824,-89125120,218205281,-490697172,1035680954,-2071361908,3936821259
%N First term of n-th difference sequence of round((k*Pi)), k >= 0.
%H Clark Kimberling, <a href="/A325846/b325846.txt">Table of n, a(n) for n = 1..200</a>
%t Table[First[Differences[Table[Round[Pi*n], {n, 0, 50}], n]], {n, 1, 50}]
%Y Cf. A325664.
%K easy,sign
%O 1,1
%A _Clark Kimberling_, Jun 09 2019