The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A038089

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A038089

Number of n-node rooted identity trees of height 5.
(history; published version)

#23 by Jon E. Schoenfield at Sat Dec 19 10:00:52 EST 2015

STATUS

editing

approved

#22 by Jon E. Schoenfield at Sat Dec 19 10:00:50 EST 2015

FORMULA

A038084 - A038083.

AUTHOR

Christian G. Bower, Jan 04 1999.

STATUS

approved

editing

#21 by Alois P. Heinz at Sun Sep 22 20:28:05 EDT 2013

STATUS

editing

approved

#20 by Alois P. Heinz at Sun Sep 22 20:25:20 EDT 2013

COMMENTS

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

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 *)

STATUS

approved

editing

#19 by Alois P. Heinz at Thu Aug 01 16:16:55 EDT 2013

STATUS

proposed

approved

#18 by Geoffrey Critzer at Thu Aug 01 15:41:36 EDT 2013

STATUS

editing

proposed

#17 by Geoffrey Critzer at Thu Aug 01 15:35:53 EDT 2013

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 *)

STATUS

approved

editing

#16 by Alois P. Heinz at Wed Jul 31 18:46:00 EDT 2013

STATUS

editing

approved

#15 by Alois P. Heinz at Wed Jul 31 18:45:58 EDT 2013

CROSSREFS

Column k=5 of A227819.

STATUS

approved

editing

#14 by Alois P. Heinz at Tue Jul 30 19:08:03 EDT 2013

STATUS

editing

approved