Concept:
The series consists of squares of consecutive prime numbers.
Step 1: Express each term as a square.
\[
4=2^2
\]
\[
9=3^2
\]
\[
25=5^2
\]
\[
49=7^2
\]
\[
121=11^2
\]
\[
169=13^2
\]
\[
289=17^2
\]
Step 2: Find the next prime.
After 17, the next prime number is 19.
\[
19^2=361
\]
Hence the next term is
\[
\boxed{361}
\]