A235180 Number of (n+1) X (2+1) 0..5 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 5, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).

212, 560, 1400, 3796, 9780, 27080, 71244, 200164, 535384, 1520236, 4122676, 11802552, 32387932, 93334500, 258770168, 749813004, 2097549460, 6106147288, 17214643468, 50312715684, 142794762392, 418766264044, 1195325876852

Offset

1,1

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +29*a(n-2) -88*a(n-3) -327*a(n-4) +1003*a(n-5) +1816*a(n-6) -5577*a(n-7) -5295*a(n-8) +15566*a(n-9) +8705*a(n-10) -20575*a(n-11) -9813*a(n-12) +12552*a(n-13) +5962*a(n-14) -3436*a(n-15) -1676*a(n-16) +336*a(n-17) +168*a(n-18).

Example

Some solutions for n=4:
  4 5 4   2 0 4   3 0 4   3 0 3   0 2 0   0 3 2   4 2 4
  5 1 5   0 3 2   2 4 3   0 2 0   4 1 4   3 1 5   1 4 1
  2 3 2   2 0 4   4 1 5   3 0 3   2 4 2   0 3 2   4 2 4
  5 1 5   0 3 2   1 3 2   0 2 0   5 2 5   3 1 5   2 5 2
  2 3 2   3 1 5   3 0 4   4 1 4   1 3 1   0 3 2   5 3 5

Crossrefs

Column 2 of A235186.

Sequence in context: A078211 A158794 A204364 * A353139 A114880 A348831

Adjacent sequences: A235177 A235178 A235179 * A235181 A235182 A235183

Keyword

nonn

Author

R. H. Hardin, Jan 04 2014

Status

approved