Consecutive Integer Number Sum

How would I solve 13-26 inclusive.

Like I can get the 1-60 or w.e but I want to know if it doesnt start at the number 1 and if the addition of both numbers is odd what are we supposed to do when finding the median and such. Thank you

You can do

[1 - 26] - [1 - 12]

to find [13 - 26]

There are other options though - the process of (median times number of elements) doesn’t change.