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A287151
Array read by antidiagonals: T(m,n) = number of nonzero m X n binary arrays with all 1's connected.
13
1, 3, 3, 6, 13, 6, 10, 40, 40, 10, 15, 108, 218, 108, 15, 21, 275, 1126, 1126, 275, 21, 28, 681, 5726, 11506, 5726, 681, 28, 36, 1664, 28992, 116166, 116166, 28992, 1664, 36, 45, 4040, 146642, 1168586, 2301877, 1168586, 146642, 4040, 45
OFFSET
1,2
COMMENTS
Also the number of connected induced (non-null) subgraphs of the grid graph P_m X P_n.
LINKS
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
Rows 2-4 are A059020, A059021, A059524.
Main diagonal is A059525.
Sequence in context: A168076 A168073 A231829 * A123140 A123289 A096572
KEYWORD
nonn,tabl
AUTHOR
Andrew Howroyd, May 20 2017
STATUS
approved