1+24(5^2+1)(5^4+1)(5^8+1)
=1+（5^2-1)(5^2+1)(5^4+1)(5^8+1)
=1+(5^4-1)(5^4+1)(5^8+1)
=1+(5^8-1)(5^8+1)
=1+(5^16-1)
=5^16