Anyone notice a problem with this photo?

[rprosperi]

(11-22-2019 01:36 PM)Logan Wrote:  Perhaps I'm being dense but I'm not understanding how this progression works. Add the first two numbers and then some multiples of one of those numbers in a geometric sequence?

It's just long, written-out multiplication. It's probably been so long since anyone here has done math this way, no one recognizes it any more, lol.