Number of forests of rooted trees of nonempty sets with n points. (Each node is a set of 1 or more points.)
1, 1, 3, 8, 24, 71, 224, 710, 2318, 7659, 25703, 87153, 298574, 1031104, 3587263
2 seqfan posts
Sat Sep 26 01:20:37 CEST 2009 [seqfan] Re: boxes in boxes