Robtex

Up: 13.33.90.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 13.33.91.0/25
Down right: 13.33.91.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
13.33.91.12	PTR	server-13-33-91-12.arn54.r.cloudfront.net
13.33.91.54	A+PTR	server-13-33-91-54.arn54.r.cloudfront.net
13.33.91.69	A+PTR	server-13-33-91-69.arn54.r.cloudfront.net
13.33.91.71	PTR	server-13-33-91-71.sin2.r.cloudfront.net
13.33.91.71	A	server-13-33-91-71.arn54.r.cloudfront.net
13.33.91.82	A	dataminr.slack.com
13.33.91.82	A	interestingvancouver.slack.com
13.33.91.82	A	ucdigitalgovernance.slack.com
13.33.91.125	PTR	server-13-33-91-125.sin2.r.cloudfront.net
13.33.91.141	A+PTR	server-13-33-91-141.arn54.r.cloudfront.net
13.33.91.166	PTR	server-13-33-91-166.sin2.r.cloudfront.net
13.33.91.166	A	server-13-33-91-166.arn54.r.cloudfront.net
13.33.91.181	A+PTR	server-13-33-91-181.arn54.r.cloudfront.net
13.33.91.190	PTR	server-13-33-91-190.sin2.r.cloudfront.net
13.33.91.203	A+PTR	server-13-33-91-203.arn54.r.cloudfront.net
13.33.91.236	A	burgertime.slack.com