cp's OEIS Frontend

A189594 Number of permutations of 1..n with displacements restricted to {-6,-5,-4,-3,-1,0,2}.

%I A189594 #7 Jun 02 2025 04:03:23
%S A189594 1,1,2,4,10,23,51,111,225,469,997,2125,4569,9742,20728,44075,93629,
%T A189594 199251,424146,902940,1922351,4091125,8706560,18528914,39433024,
%U A189594 83926690,178622780,380165386,809106324,1722001443,3664905891,7799962633
%N A189594 Number of permutations of 1..n with displacements restricted to {-6,-5,-4,-3,-1,0,2}.
%H A189594 R. H. Hardin, <a href="/A189594/b189594.txt">Table of n, a(n) for n = 1..200</a>
%F A189594 Empirical: a(n) = a(n-1) +2*a(n-3) +2*a(n-4) +5*a(n-5) +4*a(n-6) +9*a(n-7) +13*a(n-8) -5*a(n-9) +6*a(n-10) -17*a(n-11) -14*a(n-12) -2*a(n-13) -11*a(n-14) -2*a(n-15) -11*a(n-16) -4*a(n-17) -2*a(n-18) +5*a(n-19) +7*a(n-20) +2*a(n-21) +2*a(n-22) +2*a(n-23) +a(n-24) +a(n-25) +a(n-26) -a(n-27) -a(n-28)
%e A189594 Some solutions for n=11
%e A189594 ..1....4....1....1....1....1....1....2....4....1....6....1....1....5....5....4
%e A189594 ..2....7....2....6....7....5....7....8....3....5....5....2....5....3....2....3
%e A189594 ..3....1....3....3....6....4....3....1....1....6....1....7....3....1....1....1
%e A189594 ..5....2....7....2....2....2....2....5....2....2....2....4....2....2....4....2
%e A189594 ..6....3....5....5....3....3....9....3....6....3....3....3....6....6....3....6
%e A189594 ..4...10....4....4....4...11....4....4....7....4....4....6....4....4....6...10
%e A189594 .10....5...10....7....5....8....5...10....5....7....8....5....8....7....8....5
%e A189594 .11....6....6...11...11....6....6....6...11....8....9...11...11....8....9....8
%e A189594 ..7....9....9...10...10....7...10....7...10...10....7...10....7....9....7....7
%e A189594 ..8....8....8....8....8...10....8...11....8...11...10....8...10...10...10...11
%e A189594 ..9...11...11....9....9....9...11....9....9....9...11....9....9...11...11....9
%K A189594 nonn
%O A189594 1,3
%A A189594 _R. H. Hardin_ Apr 24 2011