# Do you know its property? (4)

Algebra Level 5

If $$t_{n}=8+ 6\binom{n-1}{1}+2\binom{n-1}{2}$$, then find the digit sum of $\displaystyle \large\sum_{n=1}^{1729} (t_{n}).$

Details and Assumptions:

1. $$\binom{n}{r}=\dfrac{n!}{r! \times (n-r)!}$$.

2. Digit sum refers to the sum of the digits of the number. For instance, Digit sum of 1729 is 1+7+2+9=19.

3. Assume $$\binom{n}{r}=0$$ if $$n<r$$.

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