Ulam's Spiral (Desmos)

Shows the famous coordinate spiral of integers up to 1000. The closed form of the nth coordinate pair is absurdly long and took a while to figure out!

You can also highlight the primes by clicking its folder, and observe how they line up.

www.desmos.com/calculator/e...

Recamán Sequence (Desmos)

This graph shows the sequence for which:
a(0) = 0
a(n) := a(n-1) - n if this is non-negative and not already used
a(n) := a(n-1) + n otherwise

Displays up to the 1000th term - you can also show the (n,a(n)) graph by clicking its folder.

www.desmos.com/calculator/f...

Unroll a Circle! (Desmos)

Drag the point at the top of the circle to change the diameter, the drag the D slider to unravel the circumference

Click the folder icons to show/hide the Circumference (after it's unravelled) - you can also change the picture.

www.desmos.com/calculator/a...

First post!
100 Square on Desmos - click the folder icons to show/hide different types of integer from 1 to 100 (squares, primes, Fibonacci, etc.)

www.desmos.com/calculator/5...