From: Application of discrete Fourier inter-coefficient difference for assessing genetic sequence similarity
Influenza A subtype
Frequency
H1N1
3
H1N3
1
H3N1
H3N6
H3N8
13
H4N6
25
H6N1
2
H7N3
6
H9N2
H10N7
4
H11N9
H12N5