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%I #4 Nov 20 2015 06:55:14
%S 0,4,4,22,65,193,628,1905,5929,18406,56934,176612,547378,1696245,
%T 5258441,16296976,50513593,156566213,485271504,1504098056,4661921212,
%U 14449556758,44786187665,138814082217,430252144356,1333559942209,4133348540461
%N Number of (n+1)X(3+1) arrays of permutations of 0..n*4+3 with each element having directed index change 1,1 2,2 -1,0 or 0,-1.
%C Column 3 of A264655.
%H R. H. Hardin, <a href="/A264650/b264650.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 6*a(n-2) +10*a(n-3) +4*a(n-4) -2*a(n-5) -a(n-6) +4*a(n-7) +18*a(n-8) +25*a(n-9) -8*a(n-10) -6*a(n-11) -10*a(n-12) +a(n-15)
%e Some solutions for n=4
%e ..4..2..3..7....4..2..3..7....1..2..3..7....4..2..3..7....4..5..3..7
%e ..5..6.10.11....8..0..1.11....5..0.10.11....5..0..1.11....8..0..1..2
%e .12.13..0..1...12.10..5..6...12..4.14..6...12.10.14..6...12.13.11..6
%e .16.14.15.19...16.14.15.19...16..8.15.19...16..8.15.19...16.14.15.10
%e .17.18..8..9...17.18.13..9...17.18.13..9...17.18.13..9...17.18.19..9
%Y Cf. A264655.
%K nonn
%O 1,2
%A _R. H. Hardin_, Nov 20 2015
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