A323699 Number of uncrossed knight's walks as specified in A323700, counting isomorphisms only once.

1, 8, 56, 404, 2563, 16516, 102280, 639532, 3899662

Offset: 4

Author

Hugo Pfoertner, Jan 24 2019

Keywords

• nonn
• walk
• hard
• more

Comments

First differs at a(7)=404 from A323700(7)=406, because there are two walks of length 7 trapped at both ends. If seen as unrooted walks, their path shapes become identical after path reversal and reflection.

Examples

			In algebraic chess notation, the two walks double counted in A323700(7) are
  N c4 d2 e4 c5 a4 b2 d1 c3 and N d4 c2 e3 d5 b4 a2 c1 b3.
		

Links

• Hugo Pfoertner, Illustrations of uncrossed knight's walks trapped after n moves, (2019).
• Hugo Pfoertner, Probability density for the number of moves to self-trapping, (2019).

Crossrefs

Cf. A003192, A323131, A323559, A323560, A323700.