Concrete Mathematics won't be too challenging if you have a strong background in mathematics. Still, it's one of the most pleasant and recreational book I've ever read.
Thank you for the review, looking over the index I probably know a little over half of the content of the book, and have some familiarity with another fourth (not that the latter means much). I might enjoy working through it anyway, as you suggest, and fifty fifty isn't too bad anyway. I'll try to come to a conclusion about this tomorrow, I'm currently not in a sound enough state to make this judgement.
For an introduction to algorithms, just read Cormen.
This book is certainly on my hit list, but I honestly wasn't considering reading it next. I've read the introduction and skimmed the contents and it does seem to emphasize more techniques for the development of algorithms, and existing algorithms than formalisms to analyse them but perhaps the latter was a arbitrary thing to look for anyway.
You may be interested in the companion book The Concrete Tetrahedron
Thank you for the suggestion, reading the preface this seems very much so like what I'm looking for. Unfortunately I do not have abstract algebra, or complex analysis skills which the preface claims are necessary. If this were a year or two ago I probably would have plowed into it and completed it understanding very little. I've recently been trying to act with some intellectual humility though, so perhaps this is something I can work through this in a year or two.