open System
let array1 = [| 12; 33; 46; 8; 23; 42; 41 |]
let array2 =
[| for i in 0..array1.Length do
if i % 2 = 0 then yield array1.[i] |]
printfn "%A" array2
b3BlbiBTeXN0ZW0KCmxldCBhcnJheTEgPSBbfCAxMjsgMzM7IDQ2OyA4OyAyMzsgNDI7IDQxIHxdCgpsZXQgYXJyYXkyID0gCiAgICBbfCBmb3IgaSBpbiAwLi5hcnJheTEuTGVuZ3RoIGRvCiAgICAgICAgICAgaWYgaSAlIDIgPSAwIHRoZW4geWllbGQgYXJyYXkxLltpXSB8XQoKcHJpbnRmbiAiJUEiIGFycmF5Mgo=