A certain computer program generates a sequence of numbers $${a}_{1}$$, $${a}_{2}$$, ... , $${a}_{n}$$ such that $${a}_{1}={a}_{2}={1}$$ and $${a}_{k}={a}_{k-1}+{2a}_{k-2}$$ for all integers k such that $$3 \le k\le n$$. If $$n > 6$$, then $${a}_{7}=$$ ?
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正确答案: B