This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A136796 Number of labeled marked rooted trees with n nodes. 3
 2, 16, 288, 8192, 320000, 15925248, 963780608, 68719476736, 5642219814912, 524288000000000, 54394721876836352, 6232805962420322304, 781754012972500385792, 106530593546206374264832, 15672832819200000000000000, 2475880078570760549798248448 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS A marked rooted tree is a rooted tree where each node and edge is marked as + or -. REFERENCES F. Bergeron, G. Labelle and P. Leroux, Combinatorial Species and Tree-Like Structures, Cambridge, 1998, p. 293 (4.1.60). LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..200 FORMULA E.g.f.: B(4*x)/2 where B(x) is e.g.f. of A000169. a(n) = A052764(n)*2. a(n) = 2^(2*n-1) * n^(n-1). - Vaclav Kotesovec, Mar 29 2014 MATHEMATICA Table[2^(2*n-1)*n^(n-1), {n, 1, 20}] (* Vaclav Kotesovec, Mar 29 2014 *) PROG (MAGMA) [2^(2*n-1)*n^(n-1): n in [1..20]]; // Vincenzo Librandi, Mar 29 2014 CROSSREFS Cf. A136794 (unlabeled version), A136797 (tree version). Sequence in context: A227674 A102599 A123744 * A055546 A009549 A254744 Adjacent sequences:  A136793 A136794 A136795 * A136797 A136798 A136799 KEYWORD nonn AUTHOR Christian G. Bower, Jan 21 2008 EXTENSIONS More terms from Vincenzo Librandi, Mar 29 2014 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 17 01:24 EDT 2018. Contains 316275 sequences. (Running on oeis4.)