A281056 T(n,k)=Number of nXk 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

0, 0, 0, 0, 1, 0, 1, 6, 6, 0, 2, 34, 68, 29, 0, 6, 104, 239, 376, 122, 0, 13, 251, 618, 1022, 1492, 468, 0, 29, 535, 1403, 2452, 3416, 4988, 1686, 0, 60, 1076, 2828, 5400, 7803, 10112, 15028, 5807, 0, 122, 2090, 5482, 10570, 16875, 22106, 27635, 42252, 19338, 0

Offset: 1

Author

R. H. Hardin, Jan 13 2017

Keywords

• nonn
• tabl

Comments

Table starts

.0.....0......0......1......2.......6......13......29......60......122......241

.0.....1......6.....34....104.....251.....535....1076....2090.....3956.....7353

.0.....6.....68....239....618....1403....2828....5482...10342....19136....34907

.0....29....376...1022...2452....5400...10570...19892...36616....66354...118926

.0...122...1492...3416...7803...16875...32370...59669..107693...191953...339219

.0...468...4988..10112..22106...46610...87995..159317..282552...495655...864369

.0..1686..15028..27635..58005..119205..221212..394884..689397..1191475..2050466

.0..5807..42252..71419.144283..288527..526340..926077.1596265..2721514..4625355

.0.19338.113076.177320.344972..671451.1201939.2084979.3549039..5982952.10051523

.0.62731.291660.426696.800225.1515524.2661939.4546633.7645715.12749511.21211441

Examples

			Some solutions for n=4 k=4
..0..0..1..0. .0..0..0..1. .0..1..0..1. .0..1..1..0. .0..1..0..1
..1..1..0..1. .0..1..0..1. .1..0..1..0. .0..1..0..1. .1..0..1..1
..0..1..1..0. .0..1..1..0. .1..0..0..1. .0..1..0..1. .1..0..0..1
..0..0..1..1. .0..1..0..1. .0..1..0..0. .1..0..1..1. .1..0..1..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..338

Crossrefs

Row 1 is A055243(n-4).

Formula

Empirical for column k:

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

k=2: a(n) = 9*a(n-1) -30*a(n-2) +45*a(n-3) -30*a(n-4) +9*a(n-5) -a(n-6)

k=3: a(n) = 5*a(n-1) -6*a(n-2) -4*a(n-3) +8*a(n-4) for n>6

k=4: [order 12] for n>14

k=5: [order 13] for n>16

k=6: [order 18] for n>21

k=7: [order 19] for n>23

Empirical for row n:

n=1: a(n) = 3*a(n-1) -5*a(n-3) +3*a(n-5) +a(n-6)

n=2: [order 8] for n>14

n=3: [same order 8] for n>15

n=4: [order 9] for n>17

n=5: [same order 9] for n>18

n=6: [same order 9] for n>19

n=7: [same order 9] for n>20