Logical Series. Puzzle

What is the missing numbr in this logical series?
1
2
6
42
1806
???????
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Ans:
3263442
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Exp.
Multiply the with itself BUT ONE LARGER.
1 x 1 But 1 x 2 = 2
2 x 2 not But 2 x 3 = 6
6 x 6 not But 6 x 7 = 42
42 x 43 = 1806
1806 x 1807 = Ans