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A301951 T(n,k)=Number of nXk 0..1 arrays with every element equal to 1, 2 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero. 12

%I #4 Mar 29 2018 12:46:02

%S 0,1,0,1,2,0,2,5,5,0,3,16,20,13,0,5,52,123,83,34,0,8,169,680,947,342,

%T 89,0,13,549,4070,9084,7326,1411,233,0,21,1784,23565,98839,120815,

%U 56710,5820,610,0,34,5797,138014,1029960,2406169,1608681,439078,24007,1597,0

%N T(n,k)=Number of nXk 0..1 arrays with every element equal to 1, 2 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero.

%C Table starts

%C .0....1.....1........2..........3............5...............8

%C .0....2.....5.......16.........52..........169.............549

%C .0....5....20......123........680.........4070...........23565

%C .0...13....83......947.......9084........98839.........1029960

%C .0...34...342.....7326.....120815......2406169........45013365

%C .0...89..1411....56710....1608681.....58609226......1969215107

%C .0..233..5820...439078...21418808...1427656268.....86143630040

%C .0..610.24007..3399722..285190208..34776685046...3768464135104

%C .0.1597.99026.26323903.3797277789.847137052736.164856325277648

%H R. H. Hardin, <a href="/A301951/b301951.txt">Table of n, a(n) for n = 1..364</a>

%F Empirical for column k:

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

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

%F k=3: a(n) = 4*a(n-1) +a(n-2) -2*a(n-3)

%F k=4: a(n) = 9*a(n-1) -8*a(n-2) -14*a(n-3) +4*a(n-4) +4*a(n-5) -a(n-6)

%F k=5: [order 13] for n>15

%F k=6: [order 26] for n>28

%F k=7: [order 43] for n>47

%F Empirical for row n:

%F n=1: a(n) = a(n-1) +a(n-2)

%F n=2: a(n) = 3*a(n-1) +a(n-2) -2*a(n-4) for n>6

%F n=3: [order 10] for n>12

%F n=4: [order 36] for n>40

%e Some solutions for n=5 k=4

%e ..0..0..0..0. .0..0..0..0. .0..0..1..1. .0..0..0..1. .0..0..1..1

%e ..0..1..1..0. .0..1..1..0. .0..1..1..1. .0..0..1..1. .0..1..0..1

%e ..0..0..0..0. .1..1..0..0. .0..0..1..1. .0..0..1..0. .0..0..1..0

%e ..1..1..1..1. .1..0..0..1. .1..1..1..1. .0..0..0..0. .1..1..0..0

%e ..0..0..0..0. .1..1..1..1. .0..0..0..0. .1..1..1..1. .1..1..1..1

%Y Column 2 is A001519.

%Y Row 1 is A000045(n-1).

%Y Row 2 is A232317(n-1).

%K nonn,tabl

%O 1,5

%A _R. H. Hardin_, Mar 29 2018

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Last modified April 19 16:52 EDT 2024. Contains 371794 sequences. (Running on oeis4.)