A243641 T(n,k)=Number of length n+2 0..k arrays with no three unequal elements in a row and new values 0..k introduced in 0..k order.
4, 4, 8, 4, 9, 16, 4, 9, 21, 32, 4, 9, 21, 50, 64, 4, 9, 21, 51, 120, 128, 4, 9, 21, 51, 127, 289, 256, 4, 9, 21, 51, 127, 323, 697, 512, 4, 9, 21, 51, 127, 324, 835, 1682, 1024, 4, 9, 21, 51, 127, 324, 844, 2187, 4060, 2048, 4, 9, 21, 51, 127, 324, 844, 2242, 5787, 9801, 4096, 4
Offset: 1
Examples
Some solutions for n=6 k=4 ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0 ..1....0....0....0....1....1....0....0....0....0....1....1....0....1....1....0 ..1....1....1....0....1....0....0....0....1....1....1....0....0....1....1....1 ..1....1....0....1....1....0....1....0....0....1....2....0....1....2....2....1 ..2....2....0....0....0....0....0....0....0....2....1....1....1....2....2....0 ..2....1....1....1....1....1....0....0....0....1....1....1....0....1....3....1 ..3....1....1....1....0....0....0....0....1....1....1....1....0....1....3....1 ..2....2....1....1....1....1....0....1....1....1....0....0....2....2....0....0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..9999
Formula
Empirical for column k:
k=1: a(n) = 2*a(n-1)
k=2: a(n) = 3*a(n-1) -a(n-2) -a(n-3)
k=3: a(n) = 5*a(n-1) -6*a(n-2) -2*a(n-3) +4*a(n-4)
k=4: a(n) = 7*a(n-1) -14*a(n-2) +21*a(n-4) -7*a(n-5) -6*a(n-6)
k=5: [order 8]
k=6: [order 10]
k=7: [order 12]
k=8: [order 14]
k=9: [order 16]
Comments