A364370 - OEIS

%I #14 Jun 23 2024 11:50:58

%S 0,0,0,6,160,1720,13056,82656,470016,2496384,12666880,62250496,

%T 298868736,1409660928,6556483584,30148976640,137316794368,

%U 620328091648,2782435737600,12402204475392,54971691171840,242433274675200

%N Number of chordless cycles (of length > 3) in the complement of the n-hypercube graph.

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

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

%F a(n) = 2^(n - 2)*n*Sum_{j=0..n-3} Sum_{k=3..n-j} 4*((k + 2)*2^(k - 5) - 1). - _Detlef Meya_, Jun 23 2024

%t a[n_] := 2^(n - 2)*n*Sum[Sum[4*((k + 2)*2^(k - 5) - 1),{k, 3, n-j}], {j, 0, n-3}]; Table[a[n], {n, 0, 21}] (* _Detlef Meya_, Jun 23 2024 *)

%Y Cf. A361149.

%K nonn

%O 0,4

%A _Eric W. Weisstein_, Jul 20 2023

%E a(10) from _Pontus von Brömssen_, Jul 28 2023

%E a(11) and beyond from _Detlef Meya_, Jun 23 2024