A286913 Number of edge covers in the grid graph P_n X P_n.

0, 7, 969, 2180738, 68534828391, 30833670159649637, 197887615273032627789510, 18126687290150589819559507400227, 23696879029605485832353513435527035363501, 442121584517675331278913696274915728729945474905362

Offset: 1

Author

Andrew Howroyd, May 15 2017

Keywords

• nonn

Links

• Jean-François Alcover, Table of n, a(n) for n = 1..12
• Eric Weisstein's World of Mathematics, Edge Cover
• Eric Weisstein's World of Mathematics, Grid Graph

Crossrefs

Main diagonal of A286912.

Cf. A286911.

Programs

Mathematica

A286912 = Cases[Import["https://oeis.org/A286912/b286912.txt", "Table"], {, }][[All, 2]];
a[n_] := A286912[[2 n^2 - 2 n + 1]]; a[1] = 1;
Table[a[n], {n, 1, 12}] (* Jean-François Alcover, Sep 23 2019 *)

Extensions

a(1) corrected by Andrew Howroyd, Jan 29 2023