Request To Shorten A Formula

[Mhz]

Hello, don't want to be pest on my Duplicate Questions, but I was hoping someone could give me a shorter formula for the one I have here.

I have 31 sheets representing 31 days (DAY1 - DAY31), of the calender in which I check for dupes in the Phone Number Column E6-E35 in all sheets, This is the Formula that works, but I want it shorter if Possible.. Thanks for any Help:

=SUM(COUNTIF(INDIRECT("DAY"&{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31}&"!E6:E35"),"="&E6))