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 A105819 Triangle of the numbers of different forests of m rooted trees of smallest order 2, i.e. without isolated vertices, on N labeled nodes. 0
 0, 2, 0, 9, 0, 0, 64, 12, 0, 0, 625, 180, 0, 0, 0, 7776, 2730, 120, 0, 0, 0, 117649, 46410, 3780, 0, 0, 0, 0, 2097152, 893816, 99120, 1680, 0, 0, 0, 0, 43046721, 19389384, 2600640, 90720, 0, 0, 0, 0, 0, 1000000000, 469532790, 71734320, 3654000, 30240, 0 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Forests of order N with m components, m > floor(N/2) must contain an isolated vertex since it is impossible to partition N vertices in floor(N/2) + 1 or more trees without give only one vertex to a tree. LINKS FORMULA a(n)= 0, if m > floor(N/2) (see comments), or can be calculated by the sum Num/D over the partitions of N:1K1+2K2+ ... + nKN, with exactly m parts and smallest part = 2, where Num = N!*product_{1=

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