Robtex

Up: 13.33.104.0/22
Can't show all results, try to descend to a more specific CIDR
Down left: 13.33.104.0/24
Down right: 13.33.105.0/24
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
13.33.104.101	A+PTR	server-13-33-104-101.dfw53.r.cloudfront.net
13.33.104.107	PTR	server-13-33-104-107.nrt51.r.cloudfront.net
13.33.104.107	A	server-13-33-104-107.dfw53.r.cloudfront.net
13.33.104.166	PTR	server-13-33-104-166.nrt51.r.cloudfront.net
13.33.104.234	PTR	server-13-33-104-234.dfw53.r.cloudfront.net
13.33.104.250	PTR	server-13-33-104-250.nrt51.r.cloudfront.net
13.33.104.250	A	server-13-33-104-250.dfw53.r.cloudfront.net
13.33.105.21	A+PTR	server-13-33-105-21.dfw53.r.cloudfront.net
13.33.105.29	A+PTR	server-13-33-105-29.dfw53.r.cloudfront.net
13.33.105.37	A	lundi-matin.slack.com
13.33.105.37	A	selenis-construction.slack.com
13.33.105.37	A	noblestudios.slack.com
13.33.105.58	A+PTR	server-13-33-105-58.dfw53.r.cloudfront.net
13.33.105.58	A	coffeehousecoders.slack.com
13.33.105.58	A	the-trading.slack.com
13.33.105.69	PTR	server-13-33-105-69.sea84.r.cloudfront.net
13.33.105.69	A	server-13-33-105-69.dfw53.r.cloudfront.net
13.33.105.75	PTR	server-13-33-105-75.sea84.r.cloudfront.net
13.33.105.77	A+PTR	server-13-33-105-77.dfw53.r.cloudfront.net
13.33.105.92	PTR	server-13-33-105-92.sea84.r.cloudfront.net
13.33.105.92	A	server-13-33-105-92.dfw53.r.cloudfront.net
13.33.105.100	PTR	server-13-33-105-100.sea84.r.cloudfront.net
13.33.105.115	PTR	server-13-33-105-115.dfw53.r.cloudfront.net
13.33.105.115	A	thinking-project.slack.com
13.33.105.115	A	openedx.slack.com
13.33.105.131	PTR	server-13-33-105-131.dfw53.r.cloudfront.net
13.33.105.197	A+PTR	server-13-33-105-197.dfw53.r.cloudfront.net
13.33.105.226	PTR	server-13-33-105-226.sea84.r.cloudfront.net
13.33.105.226	A	server-13-33-105-226.dfw53.r.cloudfront.net
13.33.105.235	A+PTR	server-13-33-105-235.dfw53.r.cloudfront.net