  We study the properties of the odd Catalan numbers, C_n, modulo 2^k for k >=
2. We show that there exist only k - 1 different congruences of the odd Catalan
numbers modulo 2^k. Moreover, these congruences can be obtained by C_{2^m - 1}
(mod 2^k) for m = 1, 2, ..., k - 1.
