I'm trying to use an Oracle stored procedure that takes
TABLE of NUMBER
It's been a few years since I've tried anything like this, but historically, passing esoteric types (arrays, user-defined types, tables) to .NET managed data providers has been poorly supported at best. I doubt
System.Data.OracleClient supports this. You'll probably have better luck with ODP.NET.
Worth noting: http://msdn.microsoft.com/en-us/library/77d8yct7.aspx