A278188 T(n,k)=Number of nXk 0..3 arrays with every element plus 1 mod 4 equal to some element at offset (-1,-1) (-1,0) (-1,1) (0,-1) (0,1) or (1,0), with upper left element zero.
0, 0, 0, 0, 3, 0, 0, 19, 28, 0, 0, 136, 544, 200, 0, 0, 935, 13012, 13720, 1532, 0, 0, 6381, 295190, 1075258, 347116, 11794, 0, 0, 43478, 6715738, 81691958, 91270219, 8803344, 90538, 0, 0, 296105, 152540636, 6196345742, 23124026160, 7737459027, 223230876
Offset: 1
Examples
Some solutions for n=3 k=4 ..0..3..3..0. .0..1..3..2. .0..1..0..3. .0..1..0..3. .0..3..1..0 ..1..3..2..1. .1..2..0..3. .3..2..0..3. .3..2..2..1. .1..2..2..0 ..2..2..0..1. .3..0..1..3. .1..2..2..3. .1..1..1..1. .1..2..3..3
Links
- R. H. Hardin, Table of n, a(n) for n = 1..84
Formula
Empirical for column k:
k=2: a(n) = 8*a(n-1) -4*a(n-2) +15*a(n-3) -26*a(n-4) +14*a(n-5) -16*a(n-6)
k=3: [order 27]
Empirical for row n:
n=2: a(n) = 9*a(n-1) -16*a(n-2) +9*a(n-3) -12*a(n-4) +5*a(n-5) +7*a(n-6) -4*a(n-7)
n=3: [order 43]
Comments