Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A006982
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A006982 Number of unlabeled distributive lattices with n elements.
(Formerly M0700)
+0
5
1, 1, 1, 1, 2, 3, 5, 8, 15, 26, 47, 82, 151, 269, 494, 891, 1639, 2978, 5483, 10006, 18428, 33749, 62162, 114083, 210189, 386292, 711811, 1309475, 2413144, 4442221, 8186962, 15077454, 27789108, 51193086, 94357143, 173859936, 320462062, 590555664, 1088548290, 2006193418, 3697997558, 6815841849, 12563729268, 23157428823, 42686759863, 78682454720, 145038561665, 267348052028, 492815778109, 908414736485 (list; graph; listen)
OFFSET

0,5

REFERENCES

J. Heitzig and J. Reinhold, Counting finite lattices, Algebra Universalis, 48 (2002), 43-53.

J. Heitzig and J. Reinhold, The number of unlabeled orders on fourteen elements, Order 17 (2000) no. 4, 333-341.

P. D. Lincoln, personal communication.

LINKS

J. Heitzig and J. Reinhold, Counting finite lattices, preprint no. 298, Institut fuer Mathematik, Universitaet Hanover, Germany, 1999.

M. Erne, J. Heitzig and J. Reinhold, On the number of distributive lattices, Electronic Journal of Combinatorics, 9 (2002), #R24.

Institut f. Mathematik, Univ. Hanover, Erne/Heitzig/Reinhold papers

CROSSREFS

Cf. A006981, A006966.

Adjacent sequences: A006979 A006980 A006981 this_sequence A006983 A006984 A006985

Sequence in context: A066372 A058519 A082095 this_sequence A054539 A026702 A000047

KEYWORD

hard,nonn,nice

AUTHOR

njas

EXTENSIONS

More terms from Jobst Heitzig (heitzig(AT)math.uni-hannover.de), Feb 02 2001. These were computed by the same algorithm that was used to enumerate the posets on 14 elements.

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified October 7 08:31 EDT 2008. Contains 144667 sequences.


AT&T Labs Research