3, 5, 7, 9, 11: how does the series continue?
With 13 and 15, of course, as we continue to add 2. Such repeated addition of the same number creates an "arithmetic progression."
Now, four of the five numbers in the original series are peculiar — and three are in a row: 3, 5 and 7 are prime numbers. That's not so exciting? Well,... it isn't.
Maybe we'll also find four consecutive prime numbers is an arithmetic progression; or five, ten, or twenty. How about 300? 154,065?
They all exist. In the endless list of prime numbers are arithmetic progressions of any length.
In the endless list of incoming emails are images of seemingly any size and form. How about inserting them into the progression of Google+ postings?
›› You don't have to download attached images from Gmail and upload them again in Google+ to share them in a post. Gmail lets you post them directly to your circles, specific recipients — or the world.