What is the next number in this series - 1, 2, 6, 42, 1806, ?

Question

1, 3, 8, 19,42, 89, (_)

Answer 1

3,263,442
(1806 X 1807)

Answer 2

Ans. 3263442
If previous term is 'a' then (a^2 + a ) is the next term.
As such it comes to (1806^2 + 1806).