I am looking for papers that have the similar style to Hervé Lehning's 1989 The American Mathematical Monthly article "From Experimentation to Proof" (PDF link via lehning.eu). It's like teaching-oriented papers.
Here's what the author said about the style at the end of his paper:
I described this small example in such detail because I think we do not distinguish enough between research and proofs in our teaching. Of course, we all know that mathematical activity requires an experimental phase. But, too often we imitate Bourbaki's way of writing, which hides the research and the trial phases completely. So, some students see mathematics as a dead science whereas mathematics is very much alive.