1,2,4,4,1,( )

1/2,1/4, （1^4/4)(3^4+1/4)...(19^4+1\4) \ (2^4+1/4)(2^4+1/4)(4^4+1/4). (（1^4+1/4)(3^4+1/4)(5^4+1/4).(19^4+1/4))/((2^4+1/4)(4^4+1/4) 1/3,2/3,1/3,1/4,2/4,3/4,2/4,1/4,( ),( ),( ),( ),( ),( ),( ) (1^4+1/4)*(3^4+1/4)*.(19^4+1/4)/(2^4+1/4)*(4^4+1/4).(20^4+1/ 求[(1^4+1/4)(3^4+1/4)(5^4+1/4)……(19^4+1/4)]/[(2^4+1/4)(4^4+1/ 1、1/2、1/4、1/7 1+1 2+2 3+1 4+4 51+1 数列1,2,4,4,1规律 1 2 4 4 1 ） “1”“2”“3”“4” 4(1)(2)