Odds for opponent to hit same flush

[g4p2005]

If I hold two suited and I hit the flush on flop, what are the odds for at least one of my opponents to hit the flush? Are these odds changing if the turn card is offsuit? Anyone knows the complete formula? Could anyone recommend a good book for such calculations?

[gamble4pro]

The odds you are looking for depend on the number of your opponents. The complete formula is too heavy. I will give you some partial results:
For 7 opponents, the odds for at least one of them to hit the flush (i.e. to hold two of same suit): 40.314%
For 8 opponents: 42.610%
For 9 opponents: 44.874%
Of course, the odds are changing when dealing the turn card (offsuit):
For 7 opponents: 30.505%
For 8 opponents: 32.924%
For 9 opponents: 35.306%