A relatively useless pseudo-random sequence with a period of seven bits is the result, but the point of this circuit is to educate rather than its utility. You can see it in operation in the video ...

[KK99] has created the simplest possible pseudo-random binary sequence generator, using a three-bit shift register.

PRBS (pseudorandom-binary-sequence), or PN (pseudonoise), generators find a broad range of applications in digital-data transmission (Reference 1). These circuits often comprise simple shift registers ...