P14111 [ZJCPC 2017] Chiaki Sequence
Description
Chiaki is interested in an infinite sequence $a_1,a_2,a_3,\dots$, which defined as follows:
$$a_n=\begin{cases}n & n \le 2 \\ 2 \cdot a_{n-1} & n \text{ is odd} \\ a_{n-1}+r_{n-1} & n \text{ is even}\end{cases}$$
where $r_n$ is the smallest positive integer not in the set $S_n = \{a_j-a_i | 1 \le i < j \le n\}$.
Chiaki would like to know the sum of the first $n$ terms of the sequence, i.e. $\sum\limits_{i=1}^{n}a_i$. As this number may be very large, Chiaki is only interested in its remainder modulo $(10^9+7)$.
Input Format
There are multiple test cases. The first line of input contains an integer $T$ ($1 \le T \le 1000$), indicating the number of test cases. For each test case:
The first line contains an integer $n$ ($1 \le n < 10^{100}$) without leading zeros.
Output Format
For each test case, output an integer denoting the answer.