These entries are queried from radb.net using whois, you can try my project getting these.
:AS228 route: 147.241.48.0/21 descr: DREN IPv4 origin: AS228 mnt-by: MAINT-AS668 changed: dale.geesey.ctr [at] dren.hpc.mil 20181022 #14:50:53Z source: RADB last-modified: 2023-11-13T15:54:59Z rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 147.241.64.0/21 descr: DREN IPv4 origin: AS228 mnt-by: MAINT-AS668 changed: dale.geesey.ctr [at] dren.hpc.mil 20181022 #14:50:53Z source: RADB last-modified: 2023-11-13T15:54:59Z rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 147.241.136.0/21 descr: DREN IPv4 origin: AS228 mnt-by: MAINT-AS668 changed: dale.geesey.ctr [at] dren.hpc.mil 20181022 #14:50:53Z source: RADB last-modified: 2023-11-13T15:54:59Z rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 147.241.144.0/21 descr: DREN IPv4 origin: AS228 mnt-by: MAINT-AS668 changed: dale.geesey.ctr [at] dren.hpc.mil 20181022 #14:50:53Z source: RADB last-modified: 2023-11-13T15:54:59Z rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route6: 2001:480:253::/48 descr: DREN IPv6 origin: AS228 mnt-by: MAINT-AS668 changed: dale.geesey.ctr [at] dren.hpc.mil 20181019 #13:48:00Z source: RADB last-modified: 2023-11-13T15:54:59Z rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source