3263442
The sequence works as follows:
First number is 1.
Next number is obtained by adding 1 to the current number and multiplying them together:
1 x 2 = 2.
Add 1 to this number (2 + 1 = 3) and multiply it with the current number (2),
3 x 2 = 6
Add 1 to this number ( 6 + 1 = 7) and multiply it with the current number (6),
7 x 6 = 42
Add 1 to this number (42 + 1 = 43) and multiply it with the current number (42),
43 x 42 = 1806
Add 1 to this number (1806 + 1 = 1807) and multiply it with the current number(1806),
1807 x 1806 = 3263442