A274728 T(n,k)=Number of nXk 0..2 arrays with no element equal to any value at offset (-1,-2) (-2,-1) or (-1,0) and new values introduced in order 0..2.
1, 2, 1, 5, 6, 2, 14, 24, 16, 4, 41, 96, 68, 48, 8, 122, 384, 296, 260, 144, 16, 365, 1536, 1300, 1632, 1040, 432, 32, 1094, 6144, 5728, 10368, 9308, 4132, 1296, 64, 3281, 24576, 25268, 66132, 84948, 52912, 16524, 3888, 128, 9842, 98304, 111512, 421904, 771300
Offset: 1
Examples
Some solutions for n=4 k=4 ..0..1..1..2. .0..1..2..0. .0..1..2..2. .0..1..2..1. .0..1..2..1 ..1..0..2..0. .1..0..1..2. .1..0..1..0. .1..0..1..2. .1..0..1..0 ..0..2..0..2. .0..1..0..1. .2..1..0..1. .2..1..0..1. .0..1..0..1 ..2..0..2..1. .1..2..2..2. .1..2..1..2. .1..2..1..0. .1..2..1..2
Links
- R. H. Hardin, Table of n, a(n) for n = 1..220
Crossrefs
Formula
Empirical for column k:
k=1: a(n) = 2*a(n-1) for n>2
k=2: a(n) = 3*a(n-1) for n>3
k=3: a(n) = 3*a(n-1) +4*a(n-2) +a(n-3) -3*a(n-4) -4*a(n-5) for n>7
k=4: [order 8] for n>12
k=5: [order 15] for n>19
k=6: [order 30] for n>35
k=7: [order 59] for n>65
Empirical for row n:
n=1: a(n) = 4*a(n-1) -3*a(n-2)
n=2: a(n) = 4*a(n-1) for n>2
n=3: a(n) = 6*a(n-1) -7*a(n-2) for n>3
n=4: a(n) = 8*a(n-1) -10*a(n-2) -4*a(n-3) +13*a(n-4) -7*a(n-5) +a(n-6) for n>7
n=5: [order 7] for n>9
n=6: [order 18] for n>20
n=7: [order 30] for n>34
Comments