A208430 Number of nX4 0..2 arrays with new values 0..2 introduced in row major order and no element equal to any knight-move neighbor (colorings ignoring permutations of colors).
14, 216, 339, 1292, 6416, 32813, 169899, 885540, 4617014, 24074947, 125562891, 654899967, 3415879346, 17817085346, 92933586111, 484741782266, 2528419901343, 13188283797088, 68790359883448, 358812044639010, 1871571851010931
Offset: 1
Keywords
Examples
Some solutions for n=4 ..0..0..0..0....0..0..0..1....0..0..0..1....0..0..1..2....0..0..0..1 ..1..2..2..2....1..2..1..1....1..2..1..1....0..1..1..1....1..2..1..1 ..1..1..2..1....2..2..2..1....2..2..2..1....2..2..1..0....2..2..2..1 ..1..0..0..0....1..0..0..0....0..2..0..0....0..2..0..0....1..2..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 7*a(n-1) -6*a(n-2) -11*a(n-3) -36*a(n-4) -39*a(n-5) +276*a(n-6) +153*a(n-7) -71*a(n-8) -518*a(n-9) -1682*a(n-10) +1463*a(n-11) +2788*a(n-12) -2181*a(n-13) -273*a(n-14) +1238*a(n-15) -2067*a(n-16) +301*a(n-17) +1071*a(n-18) -635*a(n-19) +133*a(n-20) +286*a(n-21) -194*a(n-22) -38*a(n-23) +80*a(n-24) -46*a(n-25) -14*a(n-26) +20*a(n-27) -4*a(n-28) for n>34
Comments