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%I #9 Apr 23 2023 22:28:42
%S 0,0,0,1,13,115,959,8876,101123,1519504,31138405,871560677,
%T 32897263307,1657411773700,111113100638331,9929019852558612,
%U 1185818207579540160,189496976724420953109,40497113442395855810240,11561238705271610991734848
%N Number of odd chordless cycles of length >4 in the n-triangular grid graph.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/OddChordlessCycle.html">Odd Chordless Cycle</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/TriangularGridGraph.html">Triangular Grid Graph</a>
%Y Cf. A297671.
%K nonn
%O 1,5
%A _Eric W. Weisstein_, Apr 23 2023
%E a(11)-a(20) from _Andrew Howroyd_, Apr 23 2023