
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
Observe the following equations:
\begin{align*}
l+2+3+…+n&= \frac {1}{2}n(n+l)\\
l+3+6+…+ \frac {1}{2}n(n+1)&= \frac {1}{6}n(n+1)(n+2)\\
1+4+10+… \frac {1}{6}n(n+1)(n+2)&= \frac {1}{24}n(n+1)(n+2)(n+3)
\end{align*}
Based on these equations, we can infer that $1+5+15+…+ \frac {1}{24}n(n+1)(n+2)(n+3)=$ \_\_\_\_\_\_.

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