Project Euler - problem 6

Unlike "Hackerrank" where the challenge is to solve a problem with a modicum of efficiency with the code you submit, in Euler you can just enter a solution -it does not matter if the code was an arcane spaguetti code written in a Sinclair ZX81. {I think this approach is valuable in education: you can still solve many problems with basic tools. You do not need to download React and Git to solve every single math problem in the world.}

"Find the difference between the sum of the squares of the first one hundred natural numbers and the square of the sum.."

Sometimes, a classic loop is all you need. Cue the efficiency brigade :-)