I have a table like below, it is a bed file of genome coordinate, I would like to keep only rows with numbers.

Input:

    1	        141009669	141009952
    9	        141016322	141016973
    GL000195.1	81719	82468
    GL000195.1	142613	142923
    GL000220.1	119445	119746
    HG115_PATCH 101957832	101958132
    HG1308_PATCH 130205069	130205369
    HG1308_PATCH 130205406	130205773
    HG748_PATCH  77577953	77578264
    X	         200983	202660
    y         205180	205702


output:

    1	        141009669	141009952
    9	        141016322	141016973
    X	         200983	202660
    y	         205180	205702


Thanks in advance!
    $ sed -n '/^[0-9,X,Y]/Ip' test.txt  
or 

    $ sed -n '/^[^A-WZ]/Ip' test.txt

    1	141009669	141009952
    9	141016322	141016973
    X	200983	202660
    y	205180	205702

with [tsv-utils][1]:

    $  tsv-filter  --iregex  '1:^[^A-WZ]' test.txt

    1	141009669	141009952
    9	141016322	141016973
    X	200983	202660
    y	205180	205702

  [1]: https://github.com/eBay/tsv-utils
