I have to admit, when I saw
Wally Wallington...(Thanks Curtis Curtington)
it crossed my mind that this was an early April Fools prank, but no, not at all. Very impressive indeed.
For fast, accurate and documented assistance in answering your questions, please read this article.
Understanding and using APPLY, (I) and (II) Paul White
Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden