When using a numbered list it is possible to specify the start number using
[@number] so that one can write
  1. one
  2. two
  20. [@20] twenty
  21. twenty one

This works OK with the HTML exporter, but in the latex exporter
the number will be one unity above the desired value.

The reason why this happens is because the \item command in the enumerate
environment in latex increments the counter before using it. Therefore,
org-mode should set the enumeration counter to the desired value minus one.

A patch is attached for the lisp/org-list.el file.

--
Darlan Cavalcante