2018 AMC 10A Problem 18

How many nonnegative integers can be written in the form a_7\cdot3^7+a_6\cdot3^6+a_5\cdot3^5+a_4\cdot3^4+a_3\cdot3^3+a_2\cdot3^2+a_1\cdot3^1+a_0\cdot3^0, where a_i\in \{-1,0,1\} for 0\le i \le 7?

\textbf{(A) } 512 \qquad \textbf{(B) } 729 \qquad \textbf{(C) } 1094 \qquad \textbf{(D) } 3281 \qquad \textbf{(E) } 59,048

Full credit goes to MAA for authoring these problems. These problems were taken on the AOPS website.