cp's OEIS Frontend

A189602 Number of permutations of 1..n with displacements restricted to {-7,-6,-5,-4,-3,0,1,2}.

%I A189602 #7 Jun 02 2025 04:04:07
%S A189602 1,1,1,4,13,35,89,221,499,1146,2755,6750,16570,40293,97355,234629,
%T A189602 565632,1365768,3303221,7992751,19333657,46743931,112983171,273083004,
%U A189602 660115058,1595837810,3858133501,9327445000,22549449187,54512990509,131783650621
%N A189602 Number of permutations of 1..n with displacements restricted to {-7,-6,-5,-4,-3,0,1,2}.
%H A189602 R. H. Hardin, <a href="/A189602/b189602.txt">Table of n, a(n) for n = 1..200</a>
%F A189602 Empirical: a(n) = a(n-1) +2*a(n-3) +5*a(n-4) +9*a(n-5) +16*a(n-6) +29*a(n-7) +41*a(n-8) +45*a(n-9) +2*a(n-10) +5*a(n-11) -67*a(n-12) -55*a(n-13) -40*a(n-14) -31*a(n-15) -31*a(n-16) -63*a(n-17) -58*a(n-18) -31*a(n-19) -25*a(n-20) +14*a(n-21) +12*a(n-22) +5*a(n-23) +3*a(n-24) +3*a(n-25) +16*a(n-26) +12*a(n-27) +4*a(n-28) +5*a(n-29) -a(n-30) -a(n-35) -a(n-36)
%e A189602 Some solutions for n=9
%e A189602 ..1....8....6....8....5....1....1....1....5....1....1....5....1....6....1....4
%e A189602 ..5....1....1....1....1....5....5....7....1....6....2....2....2....1....5....2
%e A189602 ..3....2....9....2....2....2....2....2....2....3....6....1....3....3....8....1
%e A189602 ..2....3....2....3....3....3....3....3....8....2....8....3....8....2....2....3
%e A189602 ..8....5....3....4....8....4....8....4....3....4....3....9....9....9....3....8
%e A189602 ..4....4....4....6....4....9....4....5....4....9....4....4....4....4....4....9
%e A189602 ..6....6....5....5....6....6....7....6....6....5....5....6....5....5....7....5
%e A189602 ..7....7....8....7....7....7....6....8....7....7....7....8....6....7....6....6
%e A189602 ..9....9....7....9....9....8....9....9....9....8....9....7....7....8....9....7
%K A189602 nonn
%O A189602 1,4
%A A189602 _R. H. Hardin_ Apr 24 2011