Solution to Matt Parkers Math Puzzles # 19 using Go- http://www.think-maths.co.uk/19challenge

main.go

package main

//Matt Parkers Math Puzzles number 19
//Find an integer N for which the the sum of the squares of the first N primes is divisible by N and N is greater than 19

func main() {
	//Shamelessly use a precalculated list of 38 primes
	primes := [38]int{2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163}

	sumOfSquares := 0
	//Loop through the primes to create the sum of the squares
	for i, p := range primes {
		//add the square of the prime
		sumOfSquares += (p * p)
		//Check if remainder is 0 after dividing by i+1 (as i starts from 0)
		if i > 19 && sumOfSquares%(i+1) == 0 {
			println("N:", i+1)
		}
	}
}

https://godoc.org/github.com/jbarham/primegen.go might be useful if you wanted to extend this code to find more solutions