Question

find a simple formula for the nth term for the following: 1,3,7,15,31,63,...

Answer 1

\[ \large 1=2^1-1 \]
\[ \large 3=2^2-1 \]
\[ \large 7=2^3-1 \]

Answer 2

so that would make \[a _{n}= 2^{n}-1\]

Answer 3

yes