You may not have pasted in all the output (or are running an older version of whois
client). You should see that A.COM, the one you want, is on the IANA whois server. Do this then:
$ whois -h whois.iana.org a.com % IANA WHOIS server % for more information on IANA, visit http://www.iana.org % This query returned 1 object domain: A.COM organisation: Internet Assigned Numbers Authority created: 1992-01-01 source: IANA
If you were looking to register A.COM, you can't. All the single-character domains under COM were reserved a long time ago.