1/3+1/15+1/35+1/65+.+1/17*19
数列 " 65,35,17,( ),1 " 括号里应填?
1,9,11,15,17,19,21,27,33,35,37,41,45,49,57,65,72,81质数有
1,9,11,15,17,19,21,27,33,35,37,41,45,49,57,65,72,81合数有,偶数有,3
(1/11-1/13)+(1/13-1/15)+(1/15-1/17)+(1/17_1/19)+(1/19-1/21)+
1/13*15+1/15*17+1/17*19+1/19*21、、、、、、+1/37*39=?
1+3+5+7+9+11+13+15+17+19到35=
1/3+1/15+1/35+1/63+1/99
1\3+1\15+1\35+1\63+1\99
1/1*2+1/2*3+1/3*4+…+1/1993*1994 1/3+1/15+1/35+1/63+...+1/17*
1/1*3+1/3*5+1/5*7...+1/17*19+1/19*21
1/3*1+1/3*5+1/5*7+A+1/17*19+1/19*21
1/3*1+1/3*5+1/5*7+----1/17*19+1/19*21=