A333108 - OEIS

%I #19 Sep 08 2022 08:46:25

%S 0,0,-1,-1,1,-2,-2,3,-2,-4,4,-1,-6,4,1,-8,4,4,-9,2,7,-10,0,10,-10,-4,

%T 12,-8,-8,14,-5,-12,14,-1,-16,13,4,-19,10,10,-20,6,15,-20,0,20,-18,-6,

%U 23,-15,-13,25,-9,-20,25,-2,-25,22,6,-29,17,15,-31,10,23,-31,1,29

%N a(n) = floor(n*sin(n)*cos(n)).

%C The sequence of indices of zeros begins: 0, 1, 22, 44, 355, 710, 1065, 1420, 1775, 2130, 2485, 2840, 3195, 260515, 312689.

%H David A. Corneth, <a href="/A333108/b333108.txt">Table of n, a(n) for n = 0..9999</a>

%t Table[Floor[n Sin[n] Cos[n]],{n,0,80}] (* _Harvey P. Dale_, Feb 10 2022 *)

%o (Python)

%o import math, matplotlib.pyplot as plt

%o x = [n for n in range(5000)]

%o y = [int(math.floor(n*math.cos(n)*math.sin(n))) for n in x]

%o print(y)

%o plt.show(plt.scatter(x, y, s=5))

%o (Magma) [Floor(n*Sin(n)*Cos(n)) : n in [0..80]]; // _Wesley Ivan Hurt_, Aug 19 2022

%Y Cf. A105662, A105663.

%K sign,easy,look

%O 0,6

%A _Alex Ratushnyak_, Mar 07 2020