A231748 Number of nX3 0..2 arrays with no element less than a strict majority of its horizontal, vertical, diagonal and antidiagonal neighbors.
9, 51, 589, 5106, 41288, 397219, 3745096, 34036486, 313782748, 2927905037, 27164864918, 251564198963, 2335778916642, 21695352159535, 201366887006680, 1869228803618176, 17356005419910937, 161143681489604094
Offset: 1
Keywords
Examples
Some solutions for n=5 ..0..0..0....0..1..1....2..0..0....2..0..0....0..0..0....0..0..2....0..1..2 ..1..0..1....0..0..0....2..0..0....0..0..2....0..0..0....1..0..0....0..0..1 ..0..2..2....2..0..0....0..1..1....0..0..2....0..2..2....1..1..0....0..0..2 ..0..0..1....0..0..2....0..0..1....0..0..1....2..0..2....2..0..2....2..0..1 ..2..0..0....0..1..1....0..0..1....1..0..0....0..0..0....0..0..0....0..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 9*a(n-1) -10*a(n-2) +205*a(n-3) -343*a(n-4) -3172*a(n-5) -8106*a(n-6) -19608*a(n-7) -86820*a(n-8) +105508*a(n-9) -250613*a(n-10) +525498*a(n-11) +3710627*a(n-12) +6249063*a(n-13) +11770795*a(n-14) -927423*a(n-15) -28037328*a(n-16) -60164511*a(n-17) -139179633*a(n-18) -217274117*a(n-19) -213592727*a(n-20) -140322482*a(n-21) +154891348*a(n-22) +398534065*a(n-23) +772218755*a(n-24) +811574834*a(n-25) +702028305*a(n-26) +477484534*a(n-27) -54847598*a(n-28) -371753704*a(n-29) -646008553*a(n-30) -754680367*a(n-31) -605925622*a(n-32) -423754908*a(n-33) -245157008*a(n-34) -118738252*a(n-35) -48930960*a(n-36) -12367856*a(n-37) -4600192*a(n-38) -2156032*a(n-39) -279552*a(n-40) for n>41
Comments