(In reply to What, me worry?
by Steve Herman)
Some of them do look a bit complicated.
To get from the nth square to the n+1th square we need to add n units on each of two adjacent sides, plus 1 in the corner; i.e. 2n+1.
No need to sum series or anything like that.
Posted by broll
on 2015-04-06 03:56:52