A197245 Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,0,1,1,1 for x=0,1,2,3,4.
1, 8, 3, 53, 110, 227, 1035, 2004, 7529, 20633, 53902, 172997, 474139, 1395792, 4009631, 11336881, 33563326, 95906965, 275694011, 796470870, 2294495057, 6647188965, 19110664400, 55033208033, 159018294491, 458707454692
Offset: 1
Keywords
Examples
Some solutions for n=4 ..1..0..1....1..0..1....1..0..1....1..0..1....1..0..1....1..1..0....1..0..1 ..2..2..1....3..1..2....1..2..2....2..2..1....2..1..3....0..2..1....2..1..3 ..1..1..0....1..1..0....0..1..1....1..1..0....0..1..1....1..3..1....0..1..1 ..0..2..1....0..2..1....1..2..0....0..1..1....1..2..0....2..1..0....1..1..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..200
Formula
Empirical: a(n) = a(n-2) +9*a(n-3) +26*a(n-4) +58*a(n-5) -25*a(n-6) -148*a(n-7) -104*a(n-8) -114*a(n-9) +55*a(n-10) -149*a(n-11) +186*a(n-12) -9*a(n-13) +39*a(n-14) -55*a(n-15) +21*a(n-16) +a(n-17) +2*a(n-18) -a(n-19) for n>20
Comments