A233023 Number of nX5 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, vertically, diagonally or antidiagonally, and top left element zero.
81, 2337, 92067, 3685017, 149128385, 6050598339, 245698677999, 9979662714381, 405380056659145, 16467175046293207, 668927350000203943, 27173135930635192613, 1103826618460521163805, 44839633474092471048067
Offset: 1
Keywords
Examples
Some solutions for n=3 ..0..2..0..1..0....0..1..3..3..3....0..1..0..1..1....0..0..1..3..3 ..0..0..0..0..1....1..1..3..1..1....0..1..0..1..1....1..1..1..1..3 ..0..0..0..1..1....3..3..3..1..3....0..1..1..1..1....1..1..1..3..3
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 59*a(n-1) -780*a(n-2) +619*a(n-3) +32493*a(n-4) -90013*a(n-5) -408784*a(n-6) +1361086*a(n-7) +1750387*a(n-8) -6258928*a(n-9) -3161760*a(n-10) +10671769*a(n-11) +1911277*a(n-12) -7549998*a(n-13) +65894*a(n-14) +2257616*a(n-15) -323424*a(n-16) -231416*a(n-17) +54784*a(n-18) +784*a(n-19) -480*a(n-20)
Comments