The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A317879 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A317879

Number of free pure identity multifunctions (with empty expressions allowed) with one atom and n positions.
(history; published version)

#20 by Alois P. Heinz at Wed Sep 12 12:46:23 EDT 2018

STATUS

reviewed

approved

#19 by Joerg Arndt at Wed Sep 12 12:28:30 EDT 2018

STATUS

proposed

reviewed

#18 by Andrew Howroyd at Wed Sep 12 12:26:17 EDT 2018

STATUS

editing

proposed

#17 by Andrew Howroyd at Wed Sep 12 01:14:32 EDT 2018

LINKS

Andrew Howroyd, <a href="/A317879/b317879.txt">Table of n, a(n) for n = 1..500</a>

STATUS

approved

editing

#16 by Alois P. Heinz at Tue Sep 11 21:17:12 EDT 2018

STATUS

proposed

approved

#15 by Gus Wiseman at Tue Sep 11 18:29:30 EDT 2018

STATUS

editing

proposed

#14 by Gus Wiseman at Tue Sep 11 18:29:06 EDT 2018

COMMENTS

A free pure identity multifunction (with empty expressions allowed) (IME) is either (case 1) the leaf symbol "o", or (case 2) a possibly empty expression of the form h[g_1, ..., g_k] where h is an IME, each of the g_i for i = 1, ..., k >= 0 is an IME, and for i =/!= j we have g_i =/!= g_j. The number of positions in an IME is the number of brackets [...] plus the number of o's.

Also the number of identity Mathematica expressions with one atom and n positions.

Discussion

Tue Sep 11

18:29

Gus Wiseman: Removed "Mathematica" from the name.

#13 by Gus Wiseman at Tue Sep 11 02:03:06 EDT 2018

NAME

Number of free pure identity Mathematica multifunctions (with empty expressions allowed) with one atom and n positions.

COMMENTS

An A free pure identity Mathematica expression multifunction (with empty expressions allowed) (IME) is either (case 1) the leaf symbol "o", or (case 2) a possibly empty expression of the form h[g_1, ..., g_k] where h is an IME, each of the g_i for i = 1, ..., k >= 0 is an IME, and for i != /= j we have g_i != /= g_j. The number of positions in an IME is the number of brackets [...] plus the number of o's.

STATUS

approved

editing

#12 by N. J. A. Sloane at Mon Sep 10 23:46:09 EDT 2018

STATUS

proposed

approved

#11 by Andrew Howroyd at Sat Sep 01 20:55:17 EDT 2018

STATUS

editing

proposed