The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A189601 Number of permutations of 1..n with displacements restricted to {-7,-6,-5,-4,-3,-1,0,2} 1

%I #5 Mar 31 2012 12:36:16

%S 1,1,2,4,10,23,51,117,250,524,1123,2428,5274,11493,24927,54025,117003,

%T 253155,548139,1187354,2572374,5573514,12074638,26156163,56658896,

%U 122731402,265858041,575909407,1247556710,2702508126,5854265152

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

%H R. H. Hardin, <a href="/A189601/b189601.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n) = a(n-1) +a(n-2) +a(n-3) +a(n-4) +4*a(n-5) +4*a(n-6) +7*a(n-7) +12*a(n-8) +11*a(n-9) -15*a(n-10) +a(n-11) -7*a(n-12) -14*a(n-13) +12*a(n-14) -12*a(n-15) -13*a(n-16) -5*a(n-17) -3*a(n-18) -2*a(n-19) -2*a(n-21) +2*a(n-22) +2*a(n-23) +5*a(n-24) +5*a(n-25) +a(n-26) +3*a(n-27) +2*a(n-28) +a(n-29) -a(n-30) +a(n-32) -a(n-33) -a(n-34)

%e Some solutions for n=10

%e ..1....2....1....5....1....1....1....2....5....1....1....2....1....2....2....1

%e ..5....3....2....7....9....2....5....3....3....3....2....7....9....3....5....9

%e ..4....1....6....1....4....4....4....1....1....6....3....1....3....1....1....3

%e ..2...10...10....2....2....8....2....4....2....2....4....5....2...10....4....2

%e ..3....9....3....3....3....3....3....5...10....5....9....3...10....5....3....5

%e ..7....4....4....4...10....7....6....6....4....4...10....4....4....4....6....4

%e ..8....5....5...10....5....5....7....8....7....7....5...10....5....7....8...10

%e ..6....6....9....6....6....6....8....9....6....9....6....6....6....6....9....6

%e ..9....7....7....9....7....9....9....7....9...10....7....9....7....9....7....7

%e .10....8....8....8....8...10...10...10....8....8....8....8....8....8...10....8

%K nonn

%O 1,3

%A _R. H. Hardin_ Apr 24 2011

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 2 14:37 EDT 2023. Contains 365837 sequences. (Running on oeis4.)