Description
It is the perfectly seamless piston door!
Ok, the perfection is that none of the door blocks are shown in the hallway, so a true seamless.
10 tick opening (and to seamless); 9 tick closing.
Related Schematics

Hex for-loop 2-wide version
Outputs once for every signal strength inputted. So if a signal strength of 7 is inputted, the output will flash 7 times.It has a few nice configuration options:- You can change the pulse duration of the output by increasing the delay on the repeater going into the comparator. Keep in mind that the delay on the repeater next to it needs to be equal to the delay of the repeater going into the comparator.- You can also change the delay between pulses by expanding the pulse extenderI also made a version that is one block longer and doesn't use a redstone lamp, but it is 3-wide instead of 2-wide. You can find that on my account page as well.

15 bit 5hz multiplier
It's a 15 bit 5 hz combinational multiplier

Pi Monte Carlo Integration π
A monte carlo integration to compute a PI approximation