https://x.com/Pajoca_/status/1843416764467556713

1843416764467556713.go

package main

import (
	"fmt"
	"math/big"
)

func main() {
	maxA := 100000
	maxN := 100

	factorialA := big.NewInt(1)

	for a := 1; a <= maxA; a++ {
		if a > 1 {
			factorialA.Mul(factorialA, big.NewInt(int64(a-1)))
		}

		for n := 1; n <= maxN; n++ {
			powAN := new(big.Int).Exp(big.NewInt(int64(a)), big.NewInt(int64(n-1)), nil)
			sumFactorialA := new(big.Int).Add(factorialA, big.NewInt(1))

			if sumFactorialA.Cmp(powAN) == 0 {
				fmt.Printf("a = %d, n = %d\n", a, n)
			}
		}
	}
}

A≦100000 && N≦100 結果

a = 2, n = 2
a = 3, n = 2
a = 5, n = 3