Numerical Recipes - Is this stuff legal?

[Simplicio]

I don’t think you can patent an algorithm. Just copywrite actual code.

Also, FWIW, from the 3rd edition:

Without an additional license to use the contained software, this book is intended as a text
and reference book, for reading and study purposes only. However, a restricted, limited
free license for use of the software by the individual owner of a copy of this book who
personally keyboards one or more routines into a single computer is granted under terms
described on p. xix.

So I don’t think its true you can’t copy the code into your computer for personnel use.