A239030 T(n,k)=Number of nXk 0..2 arrays with no element equal to the sum of elements to its left or one plus the sum of the elements above it, modulo 3.
1, 1, 2, 1, 3, 2, 1, 4, 4, 4, 1, 5, 7, 11, 4, 1, 6, 11, 28, 16, 8, 1, 7, 16, 59, 54, 43, 8, 1, 8, 22, 110, 149, 212, 64, 16, 1, 9, 29, 189, 354, 806, 428, 171, 16, 1, 10, 37, 306, 757, 2592, 2195, 1652, 256, 32, 1, 11, 46, 473, 1495, 7265, 9319, 11768, 3410, 683, 32, 1, 12, 56
Offset: 1
Examples
Some solutions for n=5 k=4 ..2..0..0..0....2..0..0..0....2..0..0..0....2..0..0..0....2..0..0..0 ..2..0..0..0....1..2..2..0....2..0..0..0....1..0..2..2....1..2..2..0 ..1..0..2..2....2..1..2..0....1..0..2..2....2..0..1..2....2..1..2..0 ..2..0..1..1....2..0..1..2....1..0..2..1....2..0..0..1....2..0..1..2 ..1..0..2..2....1..0..2..2....2..0..0..0....1..0..2..1....1..2..2..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..480
Formula
Empirical for column k:
k=1: a(n) = 2*a(n-2)
k=2: a(n) = 5*a(n-2) -4*a(n-4)
k=3: a(n) = 17*a(n-2) -96*a(n-4) +210*a(n-6) -152*a(n-8)
k=4: [order 18]
k=5: [order 38]
k=6: [order 90]
Empirical for row n:
n=1: a(n) = 1
n=2: a(n) = n + 1
n=3: a(n) = (1/2)*n^2 + (1/2)*n + 1
n=4: a(n) = (1/12)*n^4 - (1/6)*n^3 + (47/12)*n^2 - (29/6)*n + 5
n=5: [polynomial of degree 6] for n>1
n=6: [polynomial of degree 9] for n>2
n=7: [polynomial of degree 12] for n>3
Comments