>seq-a a's description
0 1 2 3 4 5 6 7 8
>seq-b b's description
0 1 2 3 4 5 6 7 8 9 10 11
>seq-c c's description
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
