help with one matrix

Dear R-list,

Could anybody tell me how to make one matrix as the below:

      [,1] [,2] [,3] [,4] [,5] [,6]
[1,]    -    2    3    4    5    6
[2,]    2    -    2    3    4    5
[3,]    3    2    -    2    3    4
[4,]    4    3    2    -    2    3
[5,]    5    4    3    2    -    2
[6,]    6    5    4    3    2    -

Thanks in advance,

Jose Claudio Faria
Brasil/Bahia/UESC/DCET
Estatistica Experimental/Prof. Adjunto
mails:
  joseclaudio.faria at terra.com.br
  jc_faria at uesc.br
  jc_faria at uol.com.br
tel: 73-3634.2779