refactoring happy numbers in Go

happy_numbers.go

package main

import (
        "fmt"
        "math"
)

func calc(number int, total *int) int {
        if number == 0 {
                return *total
        }
        *total += int(math.Pow(float64(number%10), float64(2)))
        return calc(number/10, total)
}

func is_happy_number(number int) bool {
        var i int
        for i = 100; i > 0; i-- {
                total := 0
                number = calc(number, &total)
                if number == 1 {
                        return true
                }
        }
        return false
}

func main() {
        for n := 1; n <= 1000; n += 1 {
                if is_happy_number(n) {
                        fmt.Printf("%d, ", n)
                }
        }
}