A234445 Number of (n+1) X (2+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 1 (constant-stress 1 X 1 tilings).

1120, 11574, 125080, 1377422, 15269704, 170001402, 1894235272, 21145362278, 235980939816, 2637191479466, 29456411908296, 329449541332294, 3682458023803816, 41215279675356394, 460998785806635720

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 16*a(n-1) +122*a(n-2) -2854*a(n-3) +3035*a(n-4) +114162*a(n-5) -324660*a(n-6) -1581792*a(n-7) +6105836*a(n-8) +6998392*a(n-9) -41646592*a(n-10) +4188416*a(n-11) +100180352*a(n-12) -55355328*a(n-13) -54337536*a(n-14) +19902720*a(n-15) +7110912*a(n-16) -1815552*a(n-17).

Example

Some solutions for n=3:
  2 2 2   2 1 4   2 0 4   1 1 1   2 3 4   2 0 2   1 1 0
  2 3 4   2 2 4   1 0 3   4 3 2   2 2 2   2 1 2   4 3 1
  2 2 2   3 2 3   2 0 2   3 3 3   2 3 4   0 0 0   1 1 0
  2 1 0   2 2 2   4 3 4   3 2 1   3 3 3   2 3 2   4 3 1

Crossrefs

Column 2 of A234450.

Sequence in context: A340790 A237689 A032777 * A222695 A032779 A028464

Adjacent sequences: A234442 A234443 A234444 * A234446 A234447 A234448

Keyword

nonn

Author

R. H. Hardin, Dec 26 2013

Status

approved