---
category_name: easy
problem_code: MAXPR
problem_name: 'Maxim and Progressions'
languages_supported:
- ADA
- ASM
- BASH
- BF
- C
- 'C99 strict'
- CAML
- CLOJ
- CLPS
- 'CPP 4.3.2'
- 'CPP 4.9.2'
- CPP14
- CS2
- D
- ERL
- FORT
- FS
- GO
- HASK
- ICK
- ICON
- JAVA
- JS
- 'LISP clisp'
- 'LISP sbcl'
- LUA
- NEM
- NICE
- NODEJS
- 'PAS fpc'
- 'PAS gpc'
- PERL
- PERL6
- PHP
- PIKE
- PRLG
- PYTH
- 'PYTH 3.4'
- RUBY
- SCALA
- 'SCM guile'
- 'SCM qobi'
- ST
- TCL
- TEXT
- WSPC
max_timelimit: '2'
source_sizelimit: '50000'
problem_author: sereja
problem_tester: null
date_added: 25-05-2013
tags:
- combinatorics
- dynamic
- easy
- june14
- sereja
editorial_url: 'http://discuss.codechef.com/problems/MAXPR'
time:
view_start_date: 1402911000
submit_start_date: 1402911000
visible_start_date: 1402911000
end_date: 1735669800
current: 1493558167
layout: problem
---
All submissions for this problem are available.### Read problems statements in [Mandarin Chinese](http://www.codechef.com/download/translated/JUNE14/mandarin/MAXPR.pdf) and [Russian](http://www.codechef.com/download/translated/JUNE14/russian/MAXPR.pdf).
Maxim likes arithmetic progressions and does not like sequences which are not arithmetic progressions.
Now he is interested in the question: how many subsequences of his sequence **a**, consisting of **n** elements, are not arithmetic progressions.
Sequence **s\[1\], s\[2\], ..., s\[k\]** is called a subsequence of sequence **a\[1\], a\[2\], ..., a\[n\]**, if there will be such increasing sequence of indices **i\[1\], i\[2\], ..., i\[k\] (1 โค i\[1\] < i\[2\] < ... < i\[k\] โค n)**, that **a\[i\[j\]\]** = **s\[j\]**. In other words, sequence **s** can be obtained from the **a** by deleting some elements.
Sequence **s\[1\], s\[2\], ..., s\[k\]** is called an arithmetic progression, if it can be represented as :
7. **s\[1\]** = **p**, where **p** โ some integer;
8. **s\[i\]** = **p + (i - 1)ยทq (i > 1)**, where **q** โ some integer.
In particular, the empty sequence or a sequence of one element is an arithmetic progression.
### Input
The first line of the input contains an integer **T** denoting the number of test cases. The description of **T** test cases follows.
The first line of each test case contains an integer **n** โ the number of elements in the sequence. The next line of the test case contains **n** integer, **a\[1\], a\[2\], ..., a\[n\]** โ elements of the sequence.
### Output
For each test case print the remainder of the division the answer on **1000000007 (10^9 + 7)**. All answers print on different lines.
### Constraints
**1 โค T โค 10**
1 โค n โค 200000
1 โค a\[i\] โค 100
### Example
<pre><b>Input:</b>
2
1
1
3
1 2 1
<b>Output:</b>
0
1
</pre>