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A038089 Number of n-node rooted identity trees of height 5. 2
1, 4, 9, 18, 34, 61, 108, 187, 318, 528, 871, 1417, 2288, 3662, 5825, 9203, 14471, 22639, 35266, 54725, 84607, 130379, 200287, 306787, 468607, 713970, 1085060, 1645181, 2488771, 3756778, 5658871, 8506900, 12763178, 19112874, 28568961, 42627442, 63493739 (list; graph; refs; listen; history; text; internal format)
OFFSET

6,2

COMMENTS

The number of terms with a(n)>0 is A038093(5)-5 = 3211260. - Alois P. Heinz, Sep 22 2013

LINKS

Alois P. Heinz, Table of n, a(n) for n = 6..1000

Index entries for sequences related to rooted trees

FORMULA

A038084 - A038083.

MAPLE

weigh:= proc(p) proc(n) local x, k; coeff(series(mul((1+x^k)^p(k), k=1..n), x, n+1), x, n) end end: wsh:= p-> n-> weigh(p)(n-1): f:= n-> `if`(n>0 and n<12, [1$3, 2$5, 1$3][n], 0): a:= (wsh@@2)(f)-wsh(f): seq(a(n), n=6..40);  # Alois P. Heinz, Sep 10 2008

MATHEMATICA

f[n_]:=Nest[CoefficientList[Series[Product[(1+x^i)^#[[i]], {i, 1, Length[#]}], {x, 0, 50}], x]&, {1}, n]; Drop[f[5]-PadRight[f[4], Length[f[5]]], 5] (* Geoffrey Critzer, Aug 01 2013 *)

CROSSREFS

Cf. A038081-A038093.

Column k=5 of A227819.

Sequence in context: A192760 A019454 A019453 * A027053 A122039 A083706

Adjacent sequences:  A038086 A038087 A038088 * A038090 A038091 A038092

KEYWORD

nonn,fini

AUTHOR

Christian G. Bower, Jan 04 1999

STATUS

approved

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Last modified August 20 03:34 EDT 2017. Contains 290823 sequences.