ok I finaly found out that: if e even is divided from all odds from the interval

[1,sqrt(e/2)) where sqrt(e/2) is even then it must be that the product of all these odds also divides e=> (2sqrt(e/8))!/(2^sqrt(e/8))*(sqrt(e/8)! divides e.

but what when (2sqrt(e/8))!/(2^sqrt(e/8))*(sqrt(e/8)! is not integer?