table: 1-101336-1
columns: Formula, Notation, T c (K), No. of Cu-O planes in unit cell, Crystal structure
Q: How many times is the formula tl 2 ba 2 cuo 6?
A: SELECT No. of Cu-O planes in unit cell FROM 1-101336-1 WHERE Formula = 'Tl 2 Ba 2 CuO 6'