A269776 T(n,k)=Number of length-n 0..k arrays with every repeated value unequal to the previous repeated value plus one mod k+1.
2, 3, 4, 4, 9, 8, 5, 16, 27, 14, 6, 25, 64, 78, 24, 7, 36, 125, 252, 222, 40, 8, 49, 216, 620, 984, 624, 66, 9, 64, 343, 1290, 3060, 3816, 1740, 108, 10, 81, 512, 2394, 7680, 15040, 14724, 4824, 176, 11, 100, 729, 4088, 16674, 45600, 73680, 56592, 13320, 286, 12, 121
Offset: 1
Examples
Some solutions for n=6 k=4 ..1. .4. .0. .3. .3. .4. .0. .4. .0. .0. .2. .0. .2. .4. .1. .0 ..4. .0. .3. .0. .0. .0. .4. .4. .4. .0. .0. .3. .2. .3. .2. .4 ..3. .1. .4. .3. .2. .0. .3. .2. .0. .3. .3. .4. .4. .1. .3. .0 ..2. .2. .4. .0. .2. .4. .3. .0. .2. .3. .1. .1. .1. .1. .1. .4 ..1. .4. .4. .3. .3. .0. .1. .3. .0. .0. .1. .3. .0. .4. .3. .0 ..2. .1. .1. .2. .4. .0. .1. .3. .1. .4. .1. .2. .3. .4. .3. .4
Links
- R. H. Hardin, Table of n, a(n) for n = 1..9999
Crossrefs
Formula
Empirical for column k (apparently a(n) = 2*k*a(n-1) -k*(k-1)*a(n-2) -k^2*a(n-3)):
k=1: a(n) = 2*a(n-1) -a(n-3)
k=2: a(n) = 4*a(n-1) -2*a(n-2) -4*a(n-3)
k=3: a(n) = 6*a(n-1) -6*a(n-2) -9*a(n-3)
k=4: a(n) = 8*a(n-1) -12*a(n-2) -16*a(n-3)
k=5: a(n) = 10*a(n-1) -20*a(n-2) -25*a(n-3)
k=6: a(n) = 12*a(n-1) -30*a(n-2) -36*a(n-3)
k=7: a(n) = 14*a(n-1) -42*a(n-2) -49*a(n-3)
Empirical for row n:
n=1: a(n) = n + 1
n=2: a(n) = n^2 + 2*n + 1
n=3: a(n) = n^3 + 3*n^2 + 3*n + 1
n=4: a(n) = n^4 + 4*n^3 + 6*n^2 + 3*n
n=5: a(n) = n^5 + 5*n^4 + 10*n^3 + 7*n^2 + n
n=6: a(n) = n^6 + 6*n^5 + 15*n^4 + 14*n^3 + 4*n^2
n=7: a(n) = n^7 + 7*n^6 + 21*n^5 + 25*n^4 + 11*n^3 + n^2
Comments