If you mean 3, 6, 9, 12 then the nth term is 3n
The number after 36912 is 36913
They can all be divided by 3
The only proper subset of a set comprising one element, is the null set.
1, 3 1, 2, 3, 6 1, 3, 9 1, 2, 3, 4, 6, 12 1, 2, 3, 4, 6, 8, 12, 16, 24, 48, 769, 1538, 2307, 3076, 4614, 6152, 9228, 12304, 18456, 36912