i.Formula = "=HYPERLINK('https://somelocation/"&i.Value&","& i.Value"')"
Has an error in the formula. At the i.Value"') you are missing &, i.Value & "'. The correct one, that 'compiles', is added below:
i.Formula = "=HYPERLINK('https://somelocation/" & i.Value & "," & i.Value & "')"
Also it is worth noting that instead of writing "&i.Value&" and let the VBA IDE add the spaces, it is better to do it yourself, eg: " & i.Value & ".
You're code has 2 flaws, you should add the last & to get a syntax correct formula, and add spaces between the " and &, or else VBA won't see it is right.
Edit; a third flaw:
The line to create the formula is wrong too. Let's break it down:
"=HYPERLINK('https://somelocation/" & i.Value & "," & i.Value & "')"
The parameter in the formula would be:
'https://somelocation/" & i.Value & "," & i.Value & "' so an output example of this line could be 'https://somelocation/1,1'. At first, I thought you are writing an URL with a comma, alright..? But then I looked at the HYPERLINK function in Excel and it requires two parameters. You are only giving one parameter. Excel formulas also expect a double quote instead of a single quote. You can escape a double quote in VBA like this "".
The correct line should be:
i.Cells(1, 1).Formula = "=HYPERLINK(""https://somelocation/" & i.Value & """,""" & i.Value & """)"