A286871 - OEIS

%I #24 Nov 23 2023 04:07:26

%S 2,5,43,647,22049,1455385,218691097,72877697369,51489351108548,

%T 76986419992442614,244445556617038272066,1683765308911934025295376

%N Number of irredundant sets in the n X n king graph.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/IrredundantSet.html">Irredundant Set</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/KingGraph.html">King Graph</a>

%t A286870 = Import["https://oeis.org/A286870/b286870.txt", "Table"][[All, 2]];

%t a[n_] := A286870[[2 n^2 - 2 n + 1]];

%t Table[a[n], {n, 1, 9}] (* _Jean-François Alcover_, Sep 23 2019 *)

%Y Main diagonal of A286870.

%Y Cf. A075550, A075709.

%K nonn,more

%O 1,1

%A _Andrew Howroyd_, Aug 02 2017

%E a(10)-a(12) from _Christian Sievers_, Nov 22 2023