cp's OEIS Frontend

A263711 Number of length n arrays of permutations of 0..n-1 with each element moved by -2 to 2 places and every four consecutive elements having its maximum within 4 of its minimum.

%I A263711 #8 Jan 02 2019 23:12:27
%S A263711 1,2,6,14,31,34,39,46,64,104,161,249,385,561,845,1254,1871,2833,4228,
%T A263711 6359,9545,14273,21453,32133,48184,72323,108363,162592,243817,365545,
%U A263711 548369,822181,1233053,1849282,2772959,4158841,6236608,9352579,14026153
%N A263711 Number of length n arrays of permutations of 0..n-1 with each element moved by -2 to 2 places and every four consecutive elements having its maximum within 4 of its minimum.
%H A263711 R. H. Hardin, <a href="/A263711/b263711.txt">Table of n, a(n) for n = 1..210</a>
%F A263711 Empirical: a(n) = a(n-1) + a(n-3) - a(n-4) + 2*a(n-5) - a(n-6) + a(n-7) for n>18.
%F A263711 Empirical g.f.: x*(1 + x + 4*x^2 + 7*x^3 + 16*x^4 - 3*x^5 - 6*x^6 - 21*x^7 - 9*x^8 - 19*x^9 - x^10 - 5*x^11 + 9*x^12 - 2*x^13 + 6*x^14 - 9*x^15 - 4*x^17) / (1 - x - x^3 + x^4 - 2*x^5 + x^6 - x^7). - _Colin Barker_, Jan 02 2019
%e A263711 Some solutions for n=7:
%e A263711 ..1....0....1....1....0....0....0....1....0....1....0....0....2....1....1....0
%e A263711 ..0....1....0....0....1....1....1....0....2....0....1....1....0....0....0....1
%e A263711 ..4....2....2....3....4....3....3....3....1....3....4....2....1....2....4....2
%e A263711 ..2....3....3....4....3....4....4....2....3....4....2....4....4....3....3....4
%e A263711 ..3....5....4....2....2....2....2....4....4....2....5....3....3....4....2....5
%e A263711 ..6....4....5....6....6....6....5....5....5....5....3....5....5....6....5....3
%e A263711 ..5....6....6....5....5....5....6....6....6....6....6....6....6....5....6....6
%Y A263711 Column 2 of A263714.
%K A263711 nonn
%O A263711 1,2
%A A263711 _R. H. Hardin_, Oct 24 2015