00:01
Okay, so we're going to be working with the factorial some more.
00:03
So let me just write down the relevant factorial values.
00:07
One factorial is one.
00:09
Two factorial is two.
00:11
Three factorial is three times two, which is six.
00:15
Four factorial is four times three times two.
00:20
So four times three factorial.
00:24
Four times six is 24.
00:26
Five factorial is five times four factorial.
00:30
So 120.
00:32
So these are the relevant factorial functions that we'll need for figuring out the terms in this sequence.
00:40
For n equals 1, we have minus 1 to the 1, so some negative number.
00:45
So negative 1 over 1 factorial plus 1, so minus 1 half...