“Doing business in this state” includes, except as prohibited under P.L. 86-272, issuing credit, debit, or travel and entertainment cards to customers in this state; regularly selling products or services of any kind or nature to customers in this state that receive the product or service in this state; regularly soliciting business from potential customers in this state; regularly performing services outside this state for which the benefits are received in this state; regularly engaging in transactions with customers in this state that involve intangible property and result in receipts flowing to the taxpayer from within this state; holding loans secured by real or tangible personal property located in this state; owning, directly or indirectly, a general or limited partnership interest in a partnership that does business in this state, regardless of the percentage of ownership; and owning, directly or indirectly, an interest in a limited liability company that does business in this state, regardless of the percentage of ownership, if the limited liability company is treated as a partnership for federal income tax purposes. A taxpayer doing business in this state for any part of the taxable year is considered to be doing business in this state for the entire taxable year.