SURFnet has setup a 4 byte AS using Quagga and is currently announcing 2
prefixes originating from AS3.5
IPv4: 188.8.131.52/20 (Worldwide visible)
IPv6: 2001:610:160::/48 (Only visible to the RIPE RIS project and is part
of a full feed from AS3.5)
I guess this IPv6 prefix is the first prefix announced from a 4byte AS.