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A038090 Number of n-node rooted identity trees of height 6. 3
1, 5, 14, 33, 72, 149, 301, 599, 1170, 2254, 4288, 8081, 15087, 27971, 51500, 94293, 171724, 311328, 562023, 1010819, 1811676, 3236959, 5766793, 10246734, 18162241, 32119542, 56682671, 99833464, 175509158, 308014335, 539675744, 944115593, 1649236884 (list; graph; refs; listen; history; text; internal format)
OFFSET

7,2

COMMENTS

The number of terms with a(n)>0 is A038093(6) - 6. - Alois P. Heinz, Sep 22 2013

LINKS

Alois P. Heinz, Table of n, a(n) for n = 7..1000

Index entries for sequences related to rooted trees

FORMULA

A038085 - A038084.

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@@3)(f)-(wsh@@2)(f): seq(a(n), n=7..37);  # 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[6]-PadRight[f[5], Length[f[6]]], 6] (* Geoffrey Critzer, Aug 01 2013 *)

CROSSREFS

Cf. A038081-A038093.

Column k=6 of A227819.

Sequence in context: A271993 A274324 A014302 * A094002 A188589 A105082

Adjacent sequences:  A038087 A038088 A038089 * A038091 A038092 A038093

KEYWORD

nonn,fini

AUTHOR

Christian G. Bower, Jan 04 1999

STATUS

approved

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Last modified January 17 20:36 EST 2020. Contains 330987 sequences. (Running on oeis4.)