A263692 - OEIS

%I #11 Jan 02 2019 23:12:14

%S 1,2,6,24,18,18,24,40,64,100,144,216,324,496,748,1136,1712,2596,3920,

%T 5940,8976,13592,20548,31104,47036,71184,107664,162916,246432,372868,

%U 564048,853400,1291012,1953232,2954892,4470512,6763184,10232036,15479600

%N Number of length n arrays of permutations of 0..n-1 with each element moved by -3 to 3 places and every three consecutive elements having its maximum within 3 of its minimum.

%H R. H. Hardin, <a href="/A263692/b263692.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) + a(n-2) - a(n-3) + a(n-4) for n>12.

%F Empirical g.f.: x*(1 + x + 3*x^2 + 17*x^3 - 11*x^4 - 20*x^5 + 6*x^6 - 8*x^7 + 2*x^9 - 4*x^10 - 4*x^11) / (1 - x - x^2 + x^3 - x^4). - _Colin Barker_, Jan 02 2019

%e Some solutions for n=7:

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

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

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

%e ..3....2....3....3....3....3....4....3....3....3....4....2....3....3....3....2

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

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

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

%Y Column 3 of A263693.

%K nonn

%O 1,2

%A _R. H. Hardin_, Oct 23 2015