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Number of (1+1)X(n+1) arrays of permutations of 0..n*2+1 with each element having index change (+-,+-) 0,0 1,1 or 1,2.
2

%I #6 Nov 10 2015 10:25:48

%S 4,20,108,465,2265,10920,52752,253176,1221305,5885873,28368956,

%T 136712788,658952404,3175970497,15307435585,73778034832,355593913600,

%U 1713880597360,8260513454657,39813787812289,191893397639092,924882430123988

%N Number of (1+1)X(n+1) arrays of permutations of 0..n*2+1 with each element having index change (+-,+-) 0,0 1,1 or 1,2.

%C Row 1 of A263964.

%H R. H. Hardin, <a href="/A263965/b263965.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 5*a(n-1) +7*a(n-4) -140*a(n-5) +33*a(n-6) -4*a(n-7) +95*a(n-8) +792*a(n-9) +41*a(n-10) -41*a(n-12) -792*a(n-13) -95*a(n-14) +4*a(n-15) -33*a(n-16) +140*a(n-17) -7*a(n-18) -5*a(n-21) +a(n-22)

%e Some solutions for n=4

%e ..6..1..9..7..8....0..1..2..6..7....6..8..9..7..4....0..7..5..6..4

%e ..5..0..3..4..2....5..3..4..8..9....5..2..0..1..3....2..3..1..8..9

%Y Cf. A263964.

%K nonn

%O 1,1

%A _R. H. Hardin_, Oct 30 2015