cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A348600 Triangle read by rows: T(n,k) is the number of (unlabeled) connected graphs with n nodes and metric dimension k, 0 <= k < n.

Original entry on oeis.org

1, 0, 1, 0, 1, 1, 0, 1, 4, 1, 0, 1, 13, 6, 1, 0, 1, 62, 39, 9, 1, 0, 1, 275, 488, 77, 11, 1, 0, 1, 1710, 8116, 1145, 130, 14, 1, 0, 1, 12061, 216432, 29958, 2415, 196, 16, 1, 0, 1, 93706, 9512947, 2026922, 78265, 4434, 276, 19, 1
Offset: 1

Views

Author

Pontus von Brömssen, Jan 26 2022

Keywords

Examples

			Triangle begins:
  n\k| 0  1     2       3       4     5    6   7  8  9
  ---+------------------------------------------------
   1 | 1
   2 | 0  1
   3 | 0  1     1
   4 | 0  1     4       1
   5 | 0  1    13       6       1
   6 | 0  1    62      39       9     1
   7 | 0  1   275     488      77    11    1
   8 | 0  1  1710    8116    1145   130   14   1
   9 | 0  1 12061  216432   29958  2415  196  16  1
  10 | 0  1 93706 9512947 2026922 78265 4434 276 19  1
		

Crossrefs

Row sums: A001349.

Formula

T(n,1) = 1 for n >= 2, because the only graphs with metric dimension 1 are the paths of positive lengths (Chartrand et al. 2000).
T(n,n-2) = A047209(n-2) = floor(5*n/2-6) for n >= 3 (follows from the complete description of graphs with n nodes and metric dimension n-2 by Chartrand et al. 2000).
T(n,n-1) = 1 for n >= 1 , because the only graph with n nodes and metric dimension n-1 is the complete graph (Chartrand et al. 2000).