Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A123551
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A123551 Triangle read by rows: T(n,k) (n >= 0, 0 <= k <= n(n-1)/2) gives number of unlabeled graphs with endpoints on n node and k edges. +0
1
1, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 1, 1, 2, 4, 3, 2, 1, 1, 1, 0, 0, 1, 1, 2, 6, 8, 13, 16, 13, 8, 5, 2, 1, 1, 1, 0, 0, 1, 1, 2, 6, 10, 22, 48, 76, 97, 102, 84, 60, 39, 20, 10, 5, 2, 1, 1, 1, 0, 0, 1, 1, 2, 6, 10, 25, 64, 152, 331, 617, 930, 1173, 1253, 1140 (list; graph; listen)
OFFSET

0,21

REFERENCES

R. W. Robinson, Numerical implementation of graph counting algorithms, AGRC Grant, Math. Dept., Univ. Newcastle, Australia, 1977.

LINKS

R. W. Robinson, Rows 0 through 16, flattened

EXAMPLE

Triangle begins:

n = 0

k = 0 : 1

******************** total (n = 0) = 1

n = 1

k = 0 : 1

******************** total (n = 1) = 1

n = 2

k = 0 : 1

k = 1 : 0

******************** total (n = 2) = 1

n = 3

k = 0 : 1

k = 1 : 0

k = 2 : 0

k = 3 : 1

******************** total (n = 3) = 2

n = 4

k = 0 : 1

k = 1 : 0

k = 2 : 0

k = 3 : 1

k = 4 : 1

k = 5 : 1

k = 6 : 1

******************** total (n = 4) = 5

CROSSREFS

Adjacent sequences: A123548 A123549 A123550 this_sequence A123552 A123553 A123554

Sequence in context: A109158 A049245 A123547 this_sequence A029717 A135567 A105972

KEYWORD

nonn,tabf

AUTHOR

njas, Nov 14 2006

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