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 A000950 Number of forests with n nodes and height at most 3. (Formerly M3025 N1225) 4
 1, 3, 16, 125, 1176, 12847, 160504, 2261289, 35464816, 612419291, 11539360944, 235469524237, 5170808565976, 121535533284999, 3043254281853496, 80852247370051793, 2270951670959226336, 67221368736302224819, 2091039845329887687136 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 REFERENCES J. Riordan, Forests of labeled trees, J. Combin. Theory, 5 (1968), 90-103. N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS T. D. Noe, Table of n, a(n) for n = 1..100 FORMULA E.g.f.: exp(x*exp(x*exp(x*exp(x)))). MATHEMATICA nn = 20; Range[0, nn]! CoefficientList[Series[Exp[x*Exp[x*Exp[x*Exp[x]]]], {x, 0, nn}], x] (* T. D. Noe, Jun 21 2012 *) CROSSREFS Cf. A000248, A000949-A000951, A052512-A052514. Column k=3 of A210725. - Alois P. Heinz, Mar 15 2013 Sequence in context: A188417 A327826 A157457 * A320254 A245012 A000951 Adjacent sequences:  A000947 A000948 A000949 * A000951 A000952 A000953 KEYWORD nonn AUTHOR EXTENSIONS More terms from Vladeta Jovovic, Apr 07 2001 STATUS approved

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Last modified October 19 14:54 EDT 2019. Contains 328223 sequences. (Running on oeis4.)