cp's OEIS Frontend

A189595 Number of permutations of 1..n with displacements restricted to {-6,-5,-4,-3,0,1,2}.

%I A189595 #7 Jun 02 2025 04:03:29
%S A189595 1,1,1,4,13,35,89,192,418,971,2336,5654,13472,31741,74468,175022,
%T A189595 413210,977502,2311729,5460828,12889416,30420888,71817384,169592184,
%U A189595 400517287,945825180,2233383719,5273484497,12451877435,29402388773,69428451013
%N A189595 Number of permutations of 1..n with displacements restricted to {-6,-5,-4,-3,0,1,2}.
%H A189595 R. H. Hardin, <a href="/A189595/b189595.txt">Table of n, a(n) for n = 1..200</a>
%F A189595 Empirical: a(n) = a(n-1) +2*a(n-3) +5*a(n-4) +8*a(n-5) +14*a(n-6) +23*a(n-7) +23*a(n-8) -2*a(n-9) -2*a(n-10) -41*a(n-11) -32*a(n-12) -19*a(n-13) -18*a(n-14) -15*a(n-15) -13*a(n-16) -a(n-17) -5*a(n-18) +13*a(n-19) +11*a(n-20) +3*a(n-21) +3*a(n-22) +2*a(n-23) +a(n-24) +a(n-26) -a(n-27) -a(n-28)
%e A189595 Some solutions for n=10
%e A189595 ..5....1....5....4....4....5....6....1....5....1....7....1....1....1....4....1
%e A189595 ..1....6....2....8....1....1....1....8....2....8....2....5....2....2....5....5
%e A189595 ..2....2....1....1....7....6....2....3....1....9....1....2....3....7....1....2
%e A189595 ..3....4...10....2....2....2....3....2....7....2....8....4....4....3....2...10
%e A189595 ..4....3....3....3....3....3....9....4....3....3....3....3...10....4....3....3
%e A189595 ..9...10....4....5...10....4....4....5....4....4....4....6....5....5....6....4
%e A189595 ..7....5....7...10....5...10....5...10...10....5....5...10....6...10...10....7
%e A189595 ..6....8....6....6....6....7....7....6....6....6....6....8....7....6....7....6
%e A189595 ..8....7....8....7....8....8....8....7....9....7....9....7....8....8....9....8
%e A189595 .10....9....9....9....9....9...10....9....8...10...10....9....9....9....8....9
%K A189595 nonn
%O A189595 1,4
%A A189595 _R. H. Hardin_ Apr 24 2011