A189586 Number of permutations of 1..n with displacements restricted to {-4,-2,-1,0,3}

1, 1, 1, 4, 10, 20, 46, 90, 185, 374, 810, 1718, 3565, 7504, 15668, 32880, 68748, 144309, 302723, 633904, 1328936, 2784579, 5837343, 12232245, 25638253, 53738027, 112620095, 236040957, 494698039, 1036837512, 2173041695, 4554382398

Offset

1,4

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = a(n-1) +a(n-3) +3*a(n-4) +5*a(n-5) +2*a(n-6) +22*a(n-7) -6*a(n-8) +8*a(n-9) +2*a(n-10) -8*a(n-11) -22*a(n-12) -7*a(n-13) -58*a(n-14) +8*a(n-15) -19*a(n-16) +a(n-17) +7*a(n-18) +14*a(n-19) +8*a(n-20) +47*a(n-21) -7*a(n-22) +7*a(n-23) -2*a(n-24) +a(n-25) -5*a(n-27) -14*a(n-28) +3*a(n-29) +a(n-32) -a(n-33) +a(n-34) +a(n-35)

Example

Some solutions for n=11
..1....3....3....3....1....5....5....5....2....1....2....2....2....3....3....1
..3....2....6....6....2....4....4....3....6....2....6....4....3....6....2....2
..5....4....4....5....7....3....3....4....7....4....4....3....4....4....7....7
..4....1....1....1....5....1....1....1....1....6....1....1....1....1....1....4
..2....6....2....2....9....2....2....2....9....5....5....6....6....2....5....5
..6....7...10...10....3....6....7....7....3....3....3....7....7...10....6....3
..7....8...11....4....4....7....8...11....4....8...11....8....9....8....4....9
..8....5....5....8....8....8....9....9....5....9...10....5....5....5....8...10
..9....9....9....9....6....9....6....6...11...10....9....9...10....9....9....6
.10...10....7....7...10...10...10...10...10....7....7...10...11....7...10...11
.11...11....8...11...11...11...11....8....8...11....8...11....8...11...11....8

Crossrefs

Sequence in context: A275358 A048008 A048019 * A019498 A237626 A020149

Adjacent sequences: A189583 A189584 A189585 * A189587 A189588 A189589

Keyword

nonn

Author

R. H. Hardin Apr 24 2011

Status

approved