I remember from The Ringworld Engineers intro that he had no intention of writing a sequel at first, but "The Ringworld Is Unstable" finally convinced him? (Not 100% sure of this memory.)
Then he had no intention of writing another sequel until someone talked on Niven-L about Teela having a child. (This memory is firmer in my brain)
no subject
Then he had no intention of writing another sequel until someone talked on Niven-L about Teela having a child. (This memory is firmer in my brain)