97871domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumber of partitions of 1 into n powers of 1/2; or (according to one definition of "binary") the number of binary rooted trees.at n=22A002572Number of n edge connected unsensed planar maps with an external face in which all internal faces are triangles.at n=19A378343Prime numbersat n=9408