# Project Euler — Problem 29 Solution

#### Problem

Con­sid­er all inte­ger com­bi­na­tions of ab for $2 \leq a \leq 5$ and $2 \leq b \leq 5$:

22=4, 23=8, 24=16, 25=32

32=9, 33=27, 34=81, 35=243

42=16, 43=64, 44=256, 45=1024

52=25, 53=125, 54=625, 55=3125

If they are then placed in numer­i­cal order, with any repeats removed, we get the fol­low­ing sequence of 15 dis­tinct terms:

4, 8, 9, 16, 25, 27, 32, 64, 81, 125, 243, 256, 625, 1024, 3125

How many dis­tinct terms are in the sequence gen­er­at­ed by ab for $2 \leq a \leq 100$ and $2 \leq b \leq 100$?

#### Solution

let getCombos a b = [2I..a] |> List.collect (fun x -> [2..b] |> List.map (fun y -> (x, y)))