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A323699
Number of uncrossed knight's walks as specified in A323700, counting isomorphisms only once.
3
1, 8, 56, 404, 2563, 16516, 102280, 639532, 3899662
OFFSET
4,2
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.
EXAMPLE
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.
CROSSREFS
KEYWORD
nonn,walk,hard,more
AUTHOR
Hugo Pfoertner, Jan 24 2019
STATUS
approved