Moving Duplicate data to a new sheet

Hi, I;ve joined to get some major help, as google for once has failed me, or I have missed something,

Basically I got a column of random numbers in Sheet A, in Sheet B, I need a formulae which would look at Column A in the Sheet A and copy or move across all the numbers which appear three or more times in Column A in Sheet A?

I have linked a test spreadsheet. Any help would be excellent, I just cant seem to work it out at all.