Sleeve pattern confusion

Hi there,
I am new to knitting and have managed to go off advice so far with my pattern but I’m now very stuck and can’t find anything to help.
For the sleeves on my cardigan the pattern says:
‘Working in st-st inc 1 st on next and following 4th row 6 times and every following 6th row until there are 60 stitches’
I really can’t work out when I should be increasing. Is it next, 4th, 6th, next, 4th, 6th repeated 3 times then just the 6th? Or is it next, 4th, 6th, 4th, 6th… Or maybe something completely different?
It will effect whether I am increasing on just one side or both.
Any help would be much appreciated, thank you.

Welcome to KH and to knitting!
Increase one stitch on the next row. Call that row 1. Then increase every 4th row for a total of 6 times. That’s rows 5,9,13,17,21 and 25.
Next, increase every 6th row. That’s rows 31,37,43 and so on until you get to 60sts.

You raise a good question. Usually for sleeves you increase at each end of the row so that the sleeve is symmetrical (2 increases per increase row). What is the name of your pattern?