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Number of length n arrays of permutations of 0..n-1 with each element moved by -2 to 2 places and equal numbers of elements moved upwards and downwards
1

%I #5 Oct 25 2015 10:26:27

%S 1,2,4,10,19,43,90,202,434,971,2133,4780,10634,23918,53667,121159,

%T 273464,619510,1404284,3190779,7256305,16529258,37686110,86028558,

%U 196547581,449479587,1028674074,2356054490,5399827384,12383951473,28417821421

%N Number of length n arrays of permutations of 0..n-1 with each element moved by -2 to 2 places and equal numbers of elements moved upwards and downwards

%C Column 2 of A263744

%H R. H. Hardin, <a href="/A263738/b263738.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=7

%e ..0....2....1....2....1....0....0....1....2....1....0....0....2....2....0....2

%e ..1....0....0....1....0....1....2....3....1....0....1....2....1....1....3....0

%e ..3....3....2....0....3....3....1....0....0....4....2....4....0....0....4....3

%e ..5....1....5....5....2....2....3....5....4....2....3....1....3....5....1....1

%e ..2....4....3....4....4....6....6....2....3....5....5....3....4....3....2....5

%e ..4....5....6....3....5....5....5....4....5....3....4....6....5....6....6....4

%e ..6....6....4....6....6....4....4....6....6....6....6....5....6....4....5....6

%Y Cf. A263744

%K nonn

%O 1,2

%A _R. H. Hardin_, Oct 25 2015