A185835 - OEIS

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A185835

T(n,k)=Half the number of nXk binary arrays with every element equal to exactly one or two of its horizontal and vertical neighbors

0, 1, 1, 1, 3, 1, 2, 10, 10, 2, 3, 23, 30, 23, 3, 5, 61, 118, 118, 61, 5, 8, 162, 393, 514, 393, 162, 8, 13, 421, 1430, 2398, 2398, 1430, 421, 13, 21, 1103, 5004, 11789, 15782, 11789, 5004, 1103, 21, 34, 2890, 17877, 54223, 98975, 98975, 54223, 17877, 2890, 34, 55

(list; table; graph; refs; listen; history; text; internal format)

OFFSET

1,5

COMMENTS

Table starts

..0....1......1.......2.........3..........5............8............13

..1....3.....10......23........61........162..........421..........1103

..1...10.....30.....118.......393.......1430.........5004.........17877

..2...23....118.....514......2398......11789........54223........257050

..3...61....393....2398.....15782......98975.......649826.......4143707

..5..162...1430...11789.....98975.....923808......7678409......68363184

..8..421...5004...54223....649826....7678409.....91052720....1073661088

.13.1103..17877..257050...4143707...68363184...1073661088...17200095426

.21.2890..63181.1213538..26679121..593948668..12644950311..278159538826

.34.7563.224324.5716561.171597547.5187350050.149729950026.4418356392225

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..219

EXAMPLE

Some solutions for 5X4 with a(1,1)=0

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

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

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

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

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

CROSSREFS

Column 1 is A000045(n-1)

Sequence in context: A305097 A316757 A055450 * A301669 A300427 A300689

Adjacent sequences: A185832 A185833 A185834 * A185836 A185837 A185838

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin Feb 05 2011

STATUS

approved