头10个数为a,b,a+b,a+2b,2a+3b,3a+5b,5a+8b,8a+13b,13a+21b,21a+34b,和为
a+b+(a+b)+(a+2b)+(2a+3b)+(3a+5b)+(5a+8b)+(8a+13b)+(13a+21b)+(21a+34b)
=55a+88b
=11*(5a+8b)
5a+8b就是第7个数
头10个数为a,b,a+b,a+2b,2a+3b,3a+5b,5a+8b,8a+13b,13a+21b,21a+34b,和为
a+b+(a+b)+(a+2b)+(2a+3b)+(3a+5b)+(5a+8b)+(8a+13b)+(13a+21b)+(21a+34b)
=55a+88b
=11*(5a+8b)
5a+8b就是第7个数