OFFSET
1,2
COMMENTS
Also the number of connected induced (non-null) subgraphs of the grid graph P_m X P_n.
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..435
Eric Weisstein's World of Mathematics, Connected Graph
Eric Weisstein's World of Mathematics, Grid Graph
Eric Weisstein's World of Mathematics, Induced Subgraph
EXAMPLE
Table starts:
====================================================================
m\n| 1 2 3 4 5 6 7
---|----------------------------------------------------------------
1 | 1 3 6 10 15 21 28 ...
2 | 3 13 40 108 275 681 1664 ...
3 | 6 40 218 1126 5726 28992 146642 ...
4 | 10 108 1126 11506 116166 1168586 11749134 ...
5 | 15 275 5726 116166 2301877 45280509 889477656 ...
6 | 21 681 28992 1168586 45280509 1732082741 66037462454 ...
7 | 28 1664 146642 11749134 889477656 66037462454 4872949974666 ...
...
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Andrew Howroyd, May 20 2017
STATUS
approved