Question

How do I find a7? Currently getting a even #

Answer 1

we know that a₁ = 1, and aₙ = aₙ₋₁ + 2, is another way of saying, we add 2 to get the next term, namely, 2 is the common difference.

$\bf n^{th}\textit{ term of an arithmetic sequence} \\\\ a_n=a_1+(n-1)d\qquad \begin{cases} n=n^{th}\ term\\ a_1=\textit{first term's value}\\ d=\textit{common difference}\\[-0.5em] \hrulefill\\ a_1=1\\ d=2\\ n=7 \end{cases} \\\\\\ a_7=1+(7-1)2\implies a_7=1+12\implies a_7=13$