[tex]3^{1} = 3[/tex]
[tex]3^{2} = [/tex] 3×3=9
[tex]3^{3} =[/tex] 9×3=27
[tex]3^{4} =[/tex] 27×3=81
[tex]3^{5} =[/tex]81×3=243
[tex]3^{6} =[/tex]243×3=729
See here, we multiply the answer before to get the next power of three. So the integers of 3 that are in the range of 3 to 1,000 are 3^1, 3^2, 3^3, 3^4, 3^5 and 3^6