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A300465 T(n,k)=Number of nXk 0..1 arrays with every element equal to 2, 3 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 7
0, 0, 0, 0, 1, 0, 0, 2, 2, 0, 0, 4, 2, 4, 0, 0, 9, 8, 8, 9, 0, 0, 19, 22, 28, 22, 19, 0, 0, 41, 68, 142, 142, 68, 41, 0, 0, 88, 212, 540, 1146, 540, 212, 88, 0, 0, 189, 652, 2585, 7456, 7456, 2585, 652, 189, 0, 0, 406, 2017, 11343, 55663, 78195, 55663, 11343, 2017, 406, 0, 0 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,8

COMMENTS

Table starts

.0...0....0.....0.......0.........0..........0............0..............0

.0...1....2.....4.......9........19.........41...........88............189

.0...2....2.....8......22........68........212..........652...........2017

.0...4....8....28.....142.......540.......2585........11343..........51501

.0...9...22...142....1146......7456......55663.......400028........2906875

.0..19...68...540....7456.....78195.....935121.....10913850......127028268

.0..41..212..2585...55663....935121...17675111....330639367.....6123205255

.0..88..652.11343..400028..10913850..330639367...9829599051...293961266876

.0.189.2017.51501.2906875.127028268.6123205255.293961266876.14061129641181

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..220

FORMULA

Empirical for column k:

k=1: a(n) = a(n-1)

k=2: a(n) = a(n-1) +2*a(n-2) +a(n-3)

k=3: [order 15]

k=4: [order 52] for n>54

EXAMPLE

Some solutions for n=5 k=4

..0..0..0..0. .0..0..1..1. .0..0..1..1. .0..0..0..0. .0..0..0..0

..0..1..0..0. .0..1..1..0. .0..0..1..1. .0..1..1..0. .0..1..0..0

..1..1..1..1. .1..1..0..0. .1..1..0..0. .1..1..0..1. .1..1..1..1

..1..0..1..1. .1..0..0..1. .1..0..0..1. .1..0..1..1. .0..0..0..1

..0..0..1..1. .0..0..1..1. .1..1..1..1. .0..0..1..1. .0..0..1..1

CROSSREFS

Column 2 is A078039(n-2).

Sequence in context: A138270 A317643 A179011 * A300646 A300776 A301400

Adjacent sequences:  A300462 A300463 A300464 * A300466 A300467 A300468

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Mar 06 2018

STATUS

approved

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Last modified July 10 14:17 EDT 2020. Contains 335576 sequences. (Running on oeis4.)