A231839 T(n,k)=Number of nXk 0..3 arrays with no element less than a strict majority of its horizontal and antidiagonal neighbors.
4, 4, 16, 16, 50, 64, 50, 188, 422, 256, 144, 760, 4508, 3823, 1024, 422, 3309, 52411, 111621, 34350, 4096, 1268, 14666, 678660, 3477361, 2836554, 308419, 16384, 3823, 64607, 8887871, 124132900, 241961326, 71178861, 2771101, 65536, 11472, 283479
Offset: 1
Examples
Some solutions for n=3 k=4 ..3..2..2..2....2..2..3..2....2..2..0..0....3..3..1..0....0..0..0..3 ..0..0..3..0....2..3..2..2....3..0..0..1....2..1..0..0....0..0..1..1 ..0..0..0..1....2..2..2..3....1..2..2..2....1..1..1..2....2..2..2..2
Links
- R. H. Hardin, Table of n, a(n) for n = 1..178
Formula
Empirical for column k:
k=1: a(n) = 4*a(n-1)
k=2: a(n) = 4*a(n-1) +34*a(n-2) +86*a(n-3) +91*a(n-4) +46*a(n-5) +11*a(n-6) +a(n-7)
k=3: [order 10] for n>11
k=4: [order 29] for n>30
k=5: [order 82] for n>83
Empirical for row n:
n=1: a(n) = 4*a(n-1) -6*a(n-2) +10*a(n-3) -5*a(n-4) +6*a(n-5) -a(n-6) +a(n-7) for n>8
n=2: [order 31] for n>32
Comments