Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A055531
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A055531 Number of labeled order relations on n nodes in which longest chain has 2 nodes. +0
2
2, 12, 86, 840, 11642, 227892, 6285806, 243593040, 13262556722, 1014466283292, 109128015915206, 16521353903210518, 3524056001906654788, 1059868947134489833998, 449831067019305306983532 (list; graph; listen)
OFFSET

2,1

REFERENCES

L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 60.

FORMULA

a(n)=A001831(n)-1.

CROSSREFS

A column or diagonal of triangle in A008285. Cf. A052296.

Adjacent sequences: A055528 A055529 A055530 this_sequence A055532 A055533 A055534

Sequence in context: A052887 A052867 A097237 this_sequence A059435 A143923 A079858

KEYWORD

easy,nonn

AUTHOR

njas, Jul 10 2000

EXTENSIONS

More terms from Vladeta Jovovic (vladeta(AT)Eunet.yu), Oct 24 2000

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 12 15:26 EDT 2008. Contains 144830 sequences.


AT&T Labs Research