Overtone Series:

 
Frequency Example Overtone Interval
1x A - 110 1 Unison
2X A - 220 2 Octave
3X E - 330 3 Perfect Fifth
4X A-440 4 Octave
5X C#-550 5 Major Third
6X E - 660
Notice it is twice E-330
6 Perfect Fifth
7X G - 770 7 Minor Seventh
8X A - 880 8 Octave
9X B - 990 9 Major Second
10X C# - 1100 10 Major Third
11X D - 1210 11 Perfect Fourth
12X E  - 1320 12 Perfect Fifth
13X F/F# - 1430 13 minor/major sixth
14X G - 1540 14 Minor Seventh
15X G# - 1650 15 Major Seventh
16X A -1760 16 Octave