A189444 Number of n X 4 array permutations with each element moving zero or one space horizontally or diagonally.

5, 61, 666, 7300, 80282, 883049, 9712873, 106834338, 1175098084, 12925203122, 142167601085, 1563737653381, 17199948722346, 189186616701220, 2080911781577162, 22888478678939969, 251756206521753553

Offset

1,1

Comments

Column 4 of A189449.

Links

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

Formula

Empirical: a(n) = 12*a(n-1) -12*a(n-2) +12*a(n-3) -12*a(n-4) +a(n-5).

Empirical g.f.: x*(5 + x - 6*x^2 - 20*x^3 + 2*x^4) / ((1 - x)*(1 - 11*x + x^2 - 11*x^3 + x^4)). - Colin Barker, May 02 2018

Example

Some solutions for 3 X 4:
..0..1..3..2....1..0..2..3....5..1..2..3....5..1..3..2....0..6..2..3
..4..5..7..6....9.10.11..7....9..0..7..6....4..0..7..6....9..4..1..7
..9..8.11.10....8..4..5..6....8..4.11.10....8..9.11.10....8.10..5.11

Crossrefs

Cf. A189449.

Sequence in context: A203358 A099666 A350973 * A373106 A217811 A217280

Adjacent sequences: A189441 A189442 A189443 * A189445 A189446 A189447

Keyword

nonn

Author

R. H. Hardin, Apr 22 2011

Status

approved