func Exercise21() uint64 {
sum := uint64(0)
for num := uint64(1); num < uint64(10000); num++ {
factors := primes.AllFactors(num)
factors = factors[0 : len(factors)-1] // shave off "self"
dn := utils.AccumulateUint64(factors)
if dn < uint64(10000) {
if lookup[dn] == num {
sum += num + dn
}
lookup[num] = dn
}
}
return sum
}
func collectabundant() { // []int {
abundant := make([]uint64, 0, 28124)
for i := uint64(2); i <= uint64(maxabundant); i++ {
sel := false
for _, a := range abundant {
if i%a == 0 {
abundant = append(abundant, i)
sel = true
}
}
if !sel {
factors := primes.AllFactors(uint64(i))
factors = factors[0 : len(factors)-1]
sum := utils.AccumulateUint64(factors)
if sum > uint64(i) {
abundant = append(abundant, i)
}
}
}
fmt.Println(abundant)
}