Number series 3, 12, 27, 48...

The terms follow $3 \times n^2$:

• $3 \times 1^2 = 3$
• $3 \times 2^2 = 12$
• $3 \times 3^2 = 27$
• $3 \times 4^2 = 48$
• $3 \times 5^2 = 75$
• $3 \times 6^2 = 108$
• $3 \times 7^2 = 147$