For a specific number that you've preselected it's (1/37) ^5

**For any number to repeat five times in a row it's one chance less (1/37)^4**

After a number has already hit twice in a row, then there's a 1/37 chance that it will hit again making it 3x in a row.

After a number has already hit three times in a row, then there's a 1/37 chance that it will hit again, making it 4x in a row.

After a number has already hit four times in a row, then there's a 1/37 chance that it will hit again, making it 5x in a row.

After a number has already hit 50 times in a row, then there's a 1/37 chance that it will hit again, making it 51x in a row.