Flow version:
HYPERLINK(LEFT($Api.Enterprise_Server_URL_610, FIND( '/services', $Api.Enterprise_Server_URL_610)) & {!$Record.AccountId}, {!$Record.Account.Name})     
     
Forula version: 
HYPERLINK(LEFT($Api.Enterprise_Server_URL_610, FIND( '/services', $Api.Enterprise_Server_URL_610)) & AccountId, Account.Name)