u

un

A2: 0
B2: 1
A3: 1
A4: 2
A5: 3
A6: 4
A7: 5
A8: 6
A9: 7
A10: 8
A11: 9
A12: 10
C2: 0.5
C3: C2 + 1
C4: C3 + 1
C5: C4 + 1
C6: C5 + 1
C7: C6 + 1
C8: C7 + 1
C9: C8 + 1
C10: C9 + 1
C11: C10 + 1