# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a198529 Showing 1-1 of 1 %I A198529 #6 Mar 31 2012 12:36:34 %S A198529 12,206,3838,74582,1481214,29737425,600187403,12144602583, %T A198529 246046084954,4987787543526,101140166737445,2051157938501522, %U A198529 41600949234763960,843764349062814286,17113771581568185569,347115075675201580800 %N A198529 Number of 2nX4 0..2 arrays with values 0..2 introduced in row major order and each element equal to exactly one horizontal or vertical neighbor %C A198529 Column 2 of A198532 %H A198529 R. H. Hardin, Table of n, a(n) for n = 1..200 %F A198529 Empirical: a(n) = 42*a(n-1) -599*a(n-2) +3637*a(n-3) -8567*a(n-4) -1138*a(n-5) +28475*a(n-6) -23674*a(n-7) -2916*a(n-8) +112776*a(n-9) -163480*a(n-10) -147783*a(n-11) -101412*a(n-12) -148912*a(n-13) +747248*a(n-14) +967680*a(n-15) -1452032*a(n-16) -4042752*a(n-17) -7405568*a(n-18) -7340032*a(n-19) -4194304*a(n-20) %e A198529 Some solutions for n=3 %e A198529 ..0..1..2..0....0..1..1..0....0..0..1..2....0..1..0..0....0..0..1..1 %e A198529 ..0..1..2..0....0..2..2..0....2..2..1..2....0..1..2..2....2..2..0..0 %e A198529 ..2..0..0..2....1..1..0..2....0..0..2..1....1..0..1..1....1..1..2..2 %e A198529 ..2..1..1..2....2..2..0..2....1..1..2..1....1..0..2..2....2..2..1..1 %e A198529 ..0..2..0..1....0..0..2..0....2..2..0..0....0..1..1..0....1..1..0..0 %e A198529 ..0..2..0..1....1..1..2..0....0..0..1..1....0..2..2..0....0..0..2..2 %K A198529 nonn %O A198529 1,1 %A A198529 _R. H. Hardin_ Oct 26 2011 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE