The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A003244 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A003244

Number of unrooted achiral trees with n nodes.
(history; published version)

#27 by N. J. A. Sloane at Mon Jun 26 22:39:34 EDT 2017

STATUS

proposed

approved

#26 by Jon E. Schoenfield at Mon Jun 26 21:02:48 EDT 2017

STATUS

editing

proposed

#25 by Jon E. Schoenfield at Mon Jun 26 21:02:44 EDT 2017

AUTHOR

N. J. A. Sloane.

STATUS

proposed

editing

#24 by Michel Marcus at Mon Jun 26 11:51:36 EDT 2017

STATUS

editing

proposed

#23 by Michel Marcus at Mon Jun 26 11:51:30 EDT 2017

FORMULA

In terms of generating functions: A003244(x) = A003241(x)-(P^2(x)-P(x^2))/(2*x^2) with P(x)=x*A003238(x). [Harary & Robinson eq 45]. - _R. J. Mathar, _, Sep 28 2011

EXTENSIONS

Extended by _R. J. Mathar, _, Sep 28 2011

STATUS

proposed

editing

#22 by Rachel Barnett at Mon Jun 26 11:22:24 EDT 2017

STATUS

editing

proposed

#21 by Rachel Barnett at Mon Jun 26 11:22:21 EDT 2017

LINKS

F. Harary and R. W. Robinson, <a href="/A002995/a002995_1.pdf">The number of achiral trees</a>, J. Reine Angew. Math., 278 (1975), 322-335. (Annotated scanned copy)

STATUS

approved

editing

#20 by Russ Cox at Fri Mar 30 16:43:45 EDT 2012

AUTHOR

_N. J. A. Sloane (njas(AT)research.att.com)_.

Discussion

Fri Mar 30

16:43

OEIS Server: https://oeis.org/edit/global/110

#19 by R. J. Mathar at Wed Sep 28 15:47:14 EDT 2011

STATUS

proposed

approved

#18 by R. J. Mathar at Wed Sep 28 15:46:57 EDT 2011

STATUS

editing

proposed