Cho http://dientuvietnam.net/cgi-bin/mimetex.cgi?n\geq{1} chứng minh rằng:
http://dientuvietnam.net/cgi-bin/mimetex.cgi?\sum\limits_{i=0}^{n-1}C_{i}^{n}\cdot\sum\limits_{j=0}^{n-1-i}C_{j}^{n-1}=4^{n-1}
Giai thừa
Started By dungCT, 16-01-2006 - 11:05
#1
Posted 16-01-2006 - 11:05
PHONG TRUNG CHI THẦN
#2
Posted 16-01-2006 - 17:44
tớ không hiểu đề,cái trong tổng là hệ số nhị thức à?Cho http://dientuvietnam.net/cgi-bin/mimetex.cgi?n\geq{1} chứng minh rằng:
http://dientuvietnam.net/cgi-bin/mimetex.cgi?\sum\limits_{i=0}^{n-1}C_{i}^{n}\cdot\sum\limits_{j=0}^{n-1-i}C_{j}^{n-1}=4^{n-1}
1728
#3
Posted 16-01-2006 - 18:58
PHONG TRUNG CHI THẦN
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