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Number of (1+2) X (n+2) arrays of permutations of 0..n*3+5 filled by rows with each element moved 0 or 1 knight moves, and rows and columns in increasing lexicographic order.
1

%I #8 Apr 23 2021 11:23:46

%S 6,40,118,354,1209,4334,14525,46022,141006,427611,1270118,3707059,

%T 10650367,30235396,84926968,236340047,652236286,1787173735,4866827711,

%U 13182285189,35538045627,95417738007,255294004187,680978483881

%N Number of (1+2) X (n+2) arrays of permutations of 0..n*3+5 filled by rows with each element moved 0 or 1 knight moves, and rows and columns in increasing lexicographic order.

%C Row 1 of A263955.

%H R. H. Hardin, <a href="/A263956/b263956.txt">Table of n, a(n) for n = 1..210</a>

%H R. H. Hardin, <a href="/A263956/a263956.txt">Empirical recurrence of order 79</a>

%F Empirical recurrence of order 79 (see link above).

%e Some solutions for n=4

%e ..0..1..2..7.15.16....0..1.13.14.15.16....0..1..2..3..8.16....0..1..2..3.15.16

%e ..6..3..8.17.14.11....2..7..4..5.10..3....6..7..4.17.14.11....6..7..8..9.14.11

%e .12.13.10..4..5..9...12..9..6.11..8.17...12.13.10.15..5..9...12.13.10..4..5.17

%Y Cf. A263955.

%K nonn

%O 1,1

%A _R. H. Hardin_, Oct 30 2015