The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A358732 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A358732

Number of labeled trees covering 2n nodes, half of which are leaves.
(history; published version)

#13 by Alois P. Heinz at Fri Aug 02 11:36:48 EDT 2024

STATUS

proposed

approved

#12 by Stefano Spezia at Fri Aug 02 11:33:42 EDT 2024

STATUS

editing

proposed

#11 by Stefano Spezia at Fri Aug 02 08:44:57 EDT 2024

MATHEMATICA

a[n_]:=StirlingS2[2*n-2, n]*(2*n)!/n!; Array[a, 14] (* Stefano Spezia, Aug 02 2024 *)

STATUS

approved

editing

#10 by Michael De Vlieger at Sat Dec 31 11:19:55 EST 2022

STATUS

reviewed

approved

#9 by Joerg Arndt at Sat Dec 31 10:58:21 EST 2022

STATUS

proposed

reviewed

#8 by Andrew Howroyd at Sat Dec 31 10:55:17 EST 2022

STATUS

editing

proposed

#7 by Andrew Howroyd at Fri Dec 30 19:12:57 EST 2022

DATA

0, 12, 720, 109200, 31752000, 15186346560, 10852244282880, 10851787634688000, 14481281691676800000, 24881574582258352358400, 53525038934303849706393600, 140958354488116955062668595200, 446153762528143389466306560000000, 1671353230826683972965623004979200000

LINKS

Andrew Howroyd, <a href="/A358732/b358732.txt">Table of n, a(n) for n = 1..100</a>

FORMULA

a(n) = A055314(2*n, n) = Stirling2(2*n-2, n)*(2*n)!/n!. - Andrew Howroyd, Dec 30 2022

PROG

(PARI) a(n) = stirling(2*n-2, n, 2)*(2*n)!/n! \\ Andrew Howroyd, Dec 30 2022

KEYWORD

nonn,more

nonn

EXTENSIONS

Terms a(6) and beyond from Andrew Howroyd, Dec 30 2022

STATUS

approved

editing

#6 by Michael De Vlieger at Fri Dec 02 13:28:56 EST 2022

STATUS

proposed

approved

#5 by Gus Wiseman at Fri Dec 02 13:02:03 EST 2022

STATUS

editing

proposed

#4 by Gus Wiseman at Fri Dec 02 03:54:31 EST 2022

CROSSREFS

The unlabeled rooted version is A185650.