大家熟知sum form i=1 to ni=1/2 n（n+1） （*） 但sum form n<sub>1</sub>=1 to n sum form i=1 to n<sub>1</sub>i=?更一般地sum form n<sub>m-1</sub>=1 to n sum form n<sub>m-z</su...大家熟知sum form i=1 to ni=1/2 n（n+1） （*） 但sum form n<sub>1</sub>=1 to n sum form i=1 to n<sub>1</sub>i=?更一般地sum form n<sub>m-1</sub>=1 to n sum form n<sub>m-z</sub>=1 to n<sub>m-1</sub>…sum form n<sub>1</sub>=1 to n<sub>2</sub> sum form i=1 to n<sub>1</sub>i=? sum form n<sub>m-1</sub>=1 to n sum form n<sub>m-z</sub>=1 to n<sub>m-1</sub>展开更多
文摘大家熟知sum form i=1 to ni=1/2 n（n+1） （*） 但sum form n<sub>1</sub>=1 to n sum form i=1 to n<sub>1</sub>i=?更一般地sum form n<sub>m-1</sub>=1 to n sum form n<sub>m-z</sub>=1 to n<sub>m-1</sub>…sum form n<sub>1</sub>=1 to n<sub>2</sub> sum form i=1 to n<sub>1</sub>i=? sum form n<sub>m-1</sub>=1 to n sum form n<sub>m-z</sub>=1 to n<sub>m-1</sub>
