Missing numbers

Hello list,

I need to track down the missing check numbers in a serie, table
contains a column for check numbers and series like this:

dbalm=# select doc_numero,doc_ckseriesfk from bdocs where doc_cta=1
dbalm-# and doc_tipo='CHE' order by doc_numero;
doc_numero | doc_ckseriesfk
------------+----------------
19200 | 856938
19201 | 856938
19215 | 856938
19216 | 856938
19219 | 856938

Missing numbers are:
from 19202 to 19214 and 19217,19218

Does anyone knows a way to get that done in SQL or plpgsql, thanks in
advance

--
Sinceramente,
Josué Maldonado.

... "De hecho el paso de compilación a objeto suele atravesar una fase
intermedia en que se genera un fichero en lenguaje ensamblador y se
invoca al programa ensamblador del sistema." -- Tutorial de C