EDIT: Adjusted for 5 gallons at 72% efficiency
Ben Edmunds of Breakside Brewery (Portland, Oregon) shared this IPA recipe, scaled to 5 gallons (19 l) for homebrewing. He says that they adjust the hops bill in their American IPAs regularly, depending on the changes in varieties between harvests and hops lots over the course of the year. The combo of Columbus, Citra, Centennial, and Chinook is one of their favored combos.
ALL-GRAIN