A240783 T(n,k)=Number of nXk 0..1 arrays with no element equal to fewer vertical neighbors than horizontal neighbors, with new values 0..1 introduced in row major order.
1, 1, 2, 1, 3, 4, 1, 4, 11, 8, 1, 6, 20, 34, 16, 1, 9, 46, 97, 111, 32, 1, 14, 97, 305, 459, 361, 64, 1, 22, 216, 959, 2167, 2187, 1172, 128, 1, 35, 472, 3033, 10150, 15332, 10442, 3809, 256, 1, 56, 1043, 9581, 47920, 106411, 108509, 49861, 12377, 512, 1, 90, 2296, 30354
Offset: 1
Examples
Some solutions for n=4 k=4 ..0..1..0..1....0..1..0..1....0..1..0..1....0..1..1..0....0..1..1..0 ..1..0..1..0....0..0..1..0....0..1..1..0....1..1..1..0....0..1..1..1 ..0..0..1..0....1..0..1..1....1..1..1..0....1..1..1..0....1..0..1..1 ..0..1..0..1....1..0..1..1....1..1..0..1....0..1..0..1....1..0..1..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..264
Formula
Empirical for column k:
k=1: a(n) = 2*a(n-1)
k=2: a(n) = 3*a(n-1) +a(n-2) -2*a(n-4)
k=3: a(n) = 5*a(n-1) -a(n-2) -a(n-3) +4*a(n-4) -4*a(n-5) -3*a(n-6) +a(n-7)
k=4: [order 22]
k=5: [order 54]
Empirical for row n:
n=1: a(n) = a(n-1)
n=2: a(n) = 2*a(n-1) -a(n-3)
n=3: a(n) = 2*a(n-1) +a(n-2) -a(n-3) -a(n-5)
n=4: [order 15]
n=5: [order 30] for n>34
n=6: [order 94]
Comments