A274895 T(n,k)=Number of nXk 0..2 arrays with no element equal to any value at offset (0,-1) (-1,-1) or (-2,0) and new values introduced in order 0..2.
1, 1, 2, 2, 4, 3, 4, 12, 7, 6, 8, 36, 16, 14, 12, 16, 108, 37, 38, 26, 24, 32, 324, 86, 104, 84, 50, 48, 64, 972, 200, 290, 275, 192, 95, 96, 128, 2916, 465, 815, 913, 753, 436, 181, 192, 256, 8748, 1081, 2291, 3064, 3017, 2049, 990, 345, 384, 512, 26244, 2513, 6434, 10337
Offset: 1
Examples
Some solutions for n=4 k=4 ..0..1..0..2. .0..1..2..0. .0..1..0..2. .0..1..2..0. .0..1..2..1 ..2..1..2..1. .1..2..0..1. .2..1..0..2. .1..2..0..1. .1..2..0..1 ..1..0..2..1. .2..0..1..2. .1..0..2..1. .1..2..1..2. .1..0..1..2 ..1..0..1..0. .2..0..1..0. .1..0..2..0. .2..0..1..2. .2..0..1..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..420
Crossrefs
Formula
Empirical for column k:
k=1: a(n) = 2*a(n-1) for n>3
k=2: a(n) = a(n-1) +2*a(n-2) -a(n-4) for n>5
k=3: a(n) = a(n-1) +4*a(n-2) -6*a(n-4) -a(n-5) +4*a(n-6) -a(n-8) for n>10
k=4: [order 16] for n>18
k=5: [order 32] for n>34
k=6: [order 64] for n>66
Empirical for row n:
n=1: a(n) = 2*a(n-1) for n>2
n=2: a(n) = 3*a(n-1) for n>2
n=3: a(n) = 3*a(n-1) -2*a(n-2) +a(n-3)
n=4: a(n) = 5*a(n-1) -9*a(n-2) +10*a(n-3) -6*a(n-4) +a(n-5) for n>6
n=5: [order 8] for n>9
n=6: [order 13] for n>14
n=7: [order 21] for n>22
Comments