A196017 T(n,k) = Number of n X k 0..4 arrays with each element equal to the number of its horizontal and vertical neighbors within one of itself.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 3, 7, 7, 3, 1, 1, 5, 13, 25, 13, 5, 1, 1, 9, 16, 27, 27, 16, 9, 1, 1, 17, 32, 91, 106, 91, 32, 17, 1, 1, 31, 65, 231, 316, 316, 231, 65, 31, 1, 1, 57, 125, 455, 835, 708, 835, 455, 125, 57, 1, 1, 105, 211, 1135, 2350, 3572, 3572, 2350

Offset

1,13

Links

R. H. Hardin, Table of n, a(n) for n = 1..312

Example

Table starts:
.1..1...1....1.....1......1.......1........1.........1..........1...........1
.1..1...1....1.....3......5.......9.......17........31.........57.........105
.1..1...2....7....13.....16......32.......65.......125........211.........390
.1..1...7...25....27.....91.....231......455......1135.......2693........6041
.1..3..13...27...106....316.....835.....2350......7232......21846.......63985
.1..5..16...91...316....708....3572....14607.....54710.....196832......782926
.1..9..32..231...835...3572...22711...100094....517009....2740712....14291156
.1.17..65..455..2350..14607..100094...670449...4760391...32900243...226381615
.1.31.125.1135..7232..54710..517009..4760391..44864449..411748723..3838635775
.1.57.211.2693.21846.196832.2740712.32900243.411748723.5122273171.64922269000
Some solutions for n=6 and k=4:
..2..2..2..0....2..2..3..2....2..3..3..2....2..2..3..2....0..2..2..2
..2..0..3..2....2..0..3..3....3..4..3..3....2..0..3..3....2..3..0..2
..3..3..3..3....3..3..3..3....3..3..0..2....3..3..4..3....3..4..3..3
..3..2..0..2....3..2..0..2....3..4..3..3....3..4..4..3....3..3..4..3
..2..0..2..2....2..0..2..2....3..4..4..3....3..4..4..3....2..0..3..3
..2..2..2..0....2..2..2..0....2..3..3..2....2..3..3..2....2..2..3..2

Crossrefs

The n-th term of the column 2 is A000213(n-2).

Sequence in context: A362377 A259844 A112707 * A343555 A251660 A279453

Adjacent sequences: A196014 A196015 A196016 * A196018 A196019 A196020

Keyword

nonn,tabl

Author

R. H. Hardin, Sep 26 2011

Status

approved