https://play.golang.org/p/pn2jBTaTNS8

  package main
  
  import (
   "fmt"
  )
  
  // return a^n
  func Power(a, n int) int {
   var i, result int
   result = 1
   for i = 0; i < n; i++ {
    result *= a
   }
   return result
  }
  
  func main() {
   fmt.Println("Hello, playground")
   x := 2
   var powers_of_x []int
   for i := 0; i < 10; i++ {
    powers_of_x = append(powers_of_x, func(x int) int { return Power(x, i) }(x))
   }
   fmt.Println(powers_of_x)
  }

  //Output:
  //Hello, playground
  //[1 2 4 8 16 32 64 128 256 512]