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A286912 Array read by antidiagonals: T(m,n) = number of edge covers in the grid graph P_m X P_n. 9
0, 1, 1, 1, 7, 1, 2, 43, 43, 2, 3, 277, 969, 277, 3, 5, 1777, 23663, 23663, 1777, 5, 8, 11407, 571099, 2180738, 571099, 11407, 8, 13, 73219, 13807469, 198906617, 198906617, 13807469, 73219, 13, 21, 469981, 333735575, 18169793971, 68534828391, 18169793971, 333735575, 469981, 21 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
1,5
LINKS
Eric Weisstein's World of Mathematics, Edge Cover
Eric Weisstein's World of Mathematics, Grid Graph
EXAMPLE
Table starts:
======================================================================
m\n| 1 2 3 4 5 6
---|------------------------------------------------------------------
1 | 0 1 1 2 3 5 ...
2 | 1 7 43 277 1777 11407 ...
3 | 1 43 969 23663 571099 13807469 ...
4 | 2 277 23663 2180738 198906617 18169793971 ...
5 | 3 1777 571099 198906617 68534828391 23650967140325 ...
6 | 5 11407 13807469 18169793971 23650967140325 30833670159649637 ...
...
CROSSREFS
Rows 1-3 are A000045(n-1), A286911, A288031.
Main diagonal is A286913.
Sequence in context: A317733 A258335 A266985 * A239807 A130875 A370112
KEYWORD
nonn,tabl
AUTHOR
Andrew Howroyd, May 15 2017
EXTENSIONS
T(1,1) corrected by Andrew Howroyd, Jun 04 2017
STATUS
approved

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Last modified April 16 17:08 EDT 2024. Contains 371749 sequences. (Running on oeis4.)