The number of ways of breaking-up 5 identical Russian Dolls of n atomic dolls, n=0..20, are [1, 1, 6, 150, 15791, 5442547, 4762077620, 8738543204786, 29476338150380267, 166824392081434701613, 1483193888081012069795493, 19709785177023094680286421698, 376477754511485610186131980496220, 10014420201202866850432679446597128835, 361363237234560693784234942104072721469903, 17300725536274010737348382801211592540394418821, 1078270212914377946924874160806876735139662310759063, 86052108583809388993084151979764362909498397720590926352, 8667074935082075174024868089466529839138418843297707436462111, 1087650281835238865776241736898789232807999849394571729968843421667, 168128608314776226625281507773606392765936490885581810165588940413828727] this took, 3781.412, seconds