These entries are queried from radb.net using whois, you can try my project getting these.
:AS21821 route: 144.121.102.0/24 origin: AS21821 descr: Akamai Technologies, Inc. mnt-by: MAINT-AS32787 changed: cromero [at] akamai.com 20200917 #02:59:08Z source: RADB last-modified: 2023-11-13T16:13:35Z rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 144.121.104.0/24 origin: AS21821 descr: Akamai Technologies, Inc. mnt-by: MAINT-AS32787 changed: cromero [at] akamai.com 20200917 #02:59:38Z source: RADB last-modified: 2023-11-13T16:13:35Z rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source route: 216.255.100.0/24 origin: AS21821 descr: Akamai Technologies, Inc. mnt-by: MAINT-AS32787 changed: cromero [at] akamai.com 20231115 # 1959Z source: RADB last-modified: 2023-11-15T19:59:03Z rpki-ov-state: valid route: 216.255.100.0/24 descr: Create a route object for customer Montefiore Medical Center origin: AS21821 mnt-by: MONT-MNT changed: franklin.perez [at] level3.com 20040319 source: LEVEL3 rpki-ov-state: valid route: 216.255.101.0/24 origin: AS21821 descr: Akamai Technologies, Inc. mnt-by: MAINT-AS32787 changed: cromero [at] akamai.com 20231115 # 1959Z source: RADB last-modified: 2023-11-15T19:59:55Z rpki-ov-state: valid route: 216.255.101.0/24 descr: Create a route object for customer Montefiore Medical Center origin: AS21821 mnt-by: MONT-MNT changed: franklin.perez [at] level3.com 20040319 source: LEVEL3 rpki-ov-state: valid