|
%I #7 Dec 27 2023 12:38:19
%S 1,4,36,196,961,5329,29584,160000,868624,4739329,25816561,140517316,
%T 765186244,4167218916,22692108321,123567013441,672885527616,
%U 3664192267264,19953231345216,108654793385121,591677262389889
%N Number of n X 2 arrays of permutations of 0..n*2-1 with each element moved a city block distance of 0 or 2.
%C Column 2 of A263424.
%H R. H. Hardin, <a href="/A263420/b263420.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 4*a(n-1) +4*a(n-2) +22*a(n-3) +14*a(n-4) -93*a(n-5) -68*a(n-6) +52*a(n-7) +32*a(n-8) +36*a(n-9) +45*a(n-10) -16*a(n-11) +8*a(n-12) -6*a(n-13) -2*a(n-14) +a(n-15).
%e Some solutions for n=4
%e ..0..5....3..5....0..5....3..1....0..5....3..2....0..1....0..5....4..1....3..2
%e ..1..4....1..7....1..4....6..0....1..3....6..4....2..3....1..3....5..0....5..0
%e ..7..2....0..6....7..6....4..2....7..6....0..1....4..5....4..2....3..6....4..1
%e ..6..3....2..4....2..3....5..7....2..4....5..7....6..7....6..7....2..7....6..7
%Y Cf. A263424.
%K nonn
%O 1,2
%A _R. H. Hardin_, Oct 17 2015
| 