Candy Distribution

WY has n kind of candy, number 1-N, The i-th kind of candy has ai. WY would like to give some of the candy to his teammate Ecry and lasten. To be fair, he hopes that Ecry’s candies are as many as lasten's in the end. How many kinds of methods are there?

The first line contains an integer T<=11 which is the number of test cases.
Then $T$ cases follow. Each case contains two lines. The first line contains one integer n(1<=n<=200). The second line contains n integers ai(1<=ai<=200)

For each test case, output a single integer (the number of ways that WY can distribute candies to his teammates, modulo 10⁹+7 ) in a single line.

2
1
2
2
1 2

2
4

Sample: a total of 4, (1) Ecry and lasten are not assigned to the candy; (2) Ecry and lasten each to a second kind of candy; (3) Ecry points to one of the first kind of candy, lasten points to a second type of candy; (4) Ecry points to a second type of candy, lasten points to one of the first kind of candy.

FZUACM

2015 Multi-University Training Contest 1