Pattern with two unknowns

In each case, multiply the number on its left by its successor (i.e. the number on the left plus one) to get the number on the right.

$1\times (1+1) = 2$

$2\times (2+1) = 6$

$3\times (3+1) =12$

$4\times (4+1) = 20$

For 5, you should get $5\times (5+1) = 30$ and for 6, we have $6\times (6+1) = 42$ . The required answer is $30 \times 42 = \boxed{1260}$ .