Usage of 'not a' and 'no'

[subhajit123]

Do these sentences mean the same thing?

1- There is not a pen on the table.

2- There is no pen on the table.

:roll:

 

[emsr2d2]

They're both possible. The first is likely to be used to negate a previous positive statement.

Paul: There's a pen on the table.
Jane: No! There's not a pen on the table.

The second is just a statement of fact.