--- In

primenumbers@yahoogroups.com,

Chris Caldwell <caldwell@...> wrote:

> There is a fine old article you should read by Herbert Wilf

> which is "What is an answer?" American Mathematical Monthly,

> 89 (1982), 289-292).

Moreover, Herb's article was productive:

> Added in proof: After reading a preprint of this article,

> Jeffrey Lagarias and Andrew Odlyzko of Bell Laboratories

> found an algorithm that computes pi(x) in time

> O(x^(3/5+eps)): a true "formula" for pi(x).

[Here, pi(x) means the number of primes not exceeding x.]

http://www.math.upenn.edu/History/obits/Herb_Wilf.html
gives an idea of his influence.

David