A370228 Number of chordless cycles in the n-triangular honeycomb bishop graph.

0, 0, 1, 7, 39, 237, 1734, 15450, 165682, 2102614, 31015311, 524013081, 10030700577, 215582832795, 5159960081308, 136564828657252, 3972563571866868, 126343835507748636, 4372455341681750061, 163953900979575446619, 6635493391775352850603, 288852182590324903158841

Offset: 1

Author

Eric W. Weisstein, Feb 12 2024

Keywords

• nonn

Links

• Andrew Howroyd, Table of n, a(n) for n = 1..200
• Stan Wagon, Graph Theory Problems from Hexagonal and Traditional Chess, The College Mathematics Journal, Vol. 45, No. 4, September 2014, pp. 278-287.
• Eric Weisstein's World of Mathematics, Chordless Cycle.
• Eric Weisstein's World of Mathematics, Triangular Honeycomb Bishop Graph.

Crossrefs

Cf. A370224.

Programs

PARI

\\ CCGenRook defined in A370224.
a(n) = subst(CCGenRook(vector(n,i,n+1-i)), y, 1) \\ Andrew Howroyd, May 27 2025

Extensions

a(12) onwards from Andrew Howroyd, May 27 2025