# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a209377 Showing 1-1 of 1 %I A209377 #9 Jul 09 2018 14:56:24 %S A209377 16,34,64,156,320,840,1792,4848,10496,28704,62464,171456,373760, %T A209377 1027200,2240512,6160128,13438976,36954624,80625664,221715456, %U A209377 483737600,1330268160,2902392832,7981559808,17414291456,47889260544,104485617664 %N A209377 1/4 the number of (n+1) X 4 0..2 arrays with every 2 X 2 subblock having distinct edge sums. %C A209377 Column 3 of A209382. %H A209377 R. H. Hardin, Table of n, a(n) for n = 1..210 %F A209377 Empirical: a(n) = 8*a(n-2) - 12*a(n-4). %F A209377 Empirical g.f.: 2*x*(8 + 17*x - 32*x^2 - 58*x^3) / ((1 - 2*x^2)*(1 - 6*x^2)). - _Colin Barker_, Jul 09 2018 %e A209377 Some solutions for n=4: %e A209377 ..0..2..0..0....1..2..2..2....1..2..1..2....2..2..1..2....0..2..2..1 %e A209377 ..1..2..1..2....0..0..1..0....0..0..0..2....1..0..0..0....0..1..0..0 %e A209377 ..0..2..0..2....1..2..2..2....1..2..1..2....2..2..1..2....2..2..2..1 %e A209377 ..0..1..0..1....0..0..1..0....0..2..0..0....1..0..0..0....0..1..0..0 %e A209377 ..2..2..2..2....1..2..2..2....1..2..1..2....2..2..1..2....2..2..2..1 %Y A209377 Cf. A209382. %K A209377 nonn %O A209377 1,1 %A A209377 _R. H. Hardin_, Mar 07 2012 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE