You can see what channels you're subscribed to by logging into the Layer3 TV Customer Portal, clicking My Account, then clicking on My Channels.
You'll see a list of all your channels, along with the number and logo for each, and whether the channel is an allHD™ channel. If you're looking for a specific channel, you can use your browser's search function (Cmd/Ctrl + F) to search by name or callsign.
Tip: You can also show your channel list as a PDF. Just click on the View as PDF button in My Channels.