I've been looking for some new problems to work on in F# to get more comfortable with the language. I've been rather slack of late because of other projects but I had a little bit of time this week. I decided it would be fun to join the crowd and play away at the problems on the project euler site. That being said, answer #1.
module Euler = let problem1() = let test i = match (0 = i % 3) || (0 = i % 5) with | true -> Some i | false -> None let targetSeq = Seq.choose test [0..999] Seq.sum targetSeq