Number of nonintersecting (or self-avoiding) rook paths joining opposite corners of an n X n grid. 1, 2, 12, 184, 8512, 1262816, 575780564, 789360053252, 3266598486981642, 41044208702632496804, 1568758030464750013214100, 182413291514248049241470885236, 64528039343270018963357185158482118, 69450664761521361664274701548907358996488 (list; graph; refs; listen; history; text; internal format)