
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
Given an arithmetic sequence $\{a_n\}$ where all terms are distinct, the sum of the first four terms $S_4=14$, and $a_1$, $a_3$, $a_7$ form a geometric sequence.  
(1) Find the general formula for the sequence $\{a_n\}$.  
(2) Let $T_n$ be the sum of the first $n$ terms of the sequence $\left\{ \frac {1}{a_{n}a_{n+1}}\right\}$. Find $T_n$.

Present the answer in LaTex format: \boxed{Your answer}
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