login
A000529
Powers of rooted tree enumerator.
(Formerly M5086 N2202)
1
20, 74, 186, 388, 721, 1236, 1995, 3072, 4554, 6542, 9152, 12516, 16783, 22120, 28713, 36768, 46512, 58194, 72086, 88484, 107709, 130108, 156055, 185952, 220230, 259350, 303804, 354116, 410843, 474576, 545941, 625600, 714252, 812634, 921522, 1041732, 1174121, 1319588, 1479075, 1653568, 1844098, 2051742, 2277624, 2522916, 2788839, 3076664, 3387713, 3723360, 4085032, 4474210
OFFSET
1,1
REFERENCES
J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 150.
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
Simon Plouffe, Approximations de séries génératrices et quelques conjectures, Dissertation, Université du Québec à Montréal, 1992; arXiv:0911.4975 [math.NT], 2009.
Simon Plouffe, 1031 Generating Functions, Appendix to Thesis, Montreal, 1992
MAPLE
A000529:=(z-2)*(3*z**3-12*z**2+18*z-10)/(z-1)**6; [Conjectured by Simon Plouffe in his 1992 dissertation.]
a:= n-> (Matrix([[0, -3, 0, 3, 4, 4]]). Matrix(6, (i, j)-> if (i=j-1) then 1 elif j=1 then [6, -15, 20, -15, 6, -1][i] else 0 fi)^n)[1, 1]: seq(a(n), n=1..24); # Alois P. Heinz, Aug 26 2008
MATHEMATICA
a[n_] := ({0, -3, 0, 3, 4, 4}.MatrixPower[Table[If[i == j-1, 1, If[j == 1, {6, -15, 20, -15, 6, -1}[[i]], 0]], {i, 1, 6}, {j, 1, 6}], n])[[1]]; Table[a[n], {n, 1, 50}] (* Jean-François Alcover, Oct 14 2014, after Alois P. Heinz *)
CROSSREFS
Sequence in context: A238026 A010008 A237617 * A238027 A005565 A320484
KEYWORD
nonn,easy
EXTENSIONS
More terms from Sean A. Irvine, Nov 14 2010
STATUS
approved