sequence parameters sems to be out of sync with the sequence

Hello all:

I am trying to explain this. The nextval from the sequence (1734) is lower than the sequence's last number (1761).  

select aivs.CRDMBR_VLDTN_REQ_ID_SEQ.nextval from dual;

   NEXTVAL

----------

      1734

select * from dba_sequences where sequence_name = 'CRDMBR_VLDTN_REQ_ID_SEQ';

SEQUENCE_OWNER                 SEQUENCE_NAME                   MIN_VALUE  MAX_VALUE INCREMENT_BY C O CACHE_SIZE LAST_NUMBER

------------------------------ ------------------------------ ---------- ---------- ------------ - - ---------- -----------

AIVS                           CRDMBR_VLDTN_REQ_ID_SEQ                 1 1.0000E+28            1 N N         20        1761

what could be the reason for this? (oracle 11.2.0.3)

thank you

Gene