A234559 Number of (n+1) X (3+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4 (constant-stress 1 X 1 tilings).

618, 1240, 2390, 5710, 12750, 33946, 83438, 238306, 621918, 1862530, 5040110, 15596050, 43132350, 136586626, 382788878, 1232735026, 3483571038, 11361560290, 32277779630, 106316188690, 303091761150, 1006241261506, 2875220234318

Offset

1,1

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +30*a(n-2) -132*a(n-3) -331*a(n-4) +1720*a(n-5) +1530*a(n-6) -11280*a(n-7) -1324*a(n-8) +39136*a(n-9) -12360*a(n-10) -67968*a(n-11) +39456*a(n-12) +46080*a(n-13) -34560*a(n-14).

Example

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

Crossrefs

Column 3 of A234564.

Sequence in context: A275739 A108818 A288412 * A251323 A020377 A210887

Adjacent sequences: A234556 A234557 A234558 * A234560 A234561 A234562

Keyword

nonn

Author

R. H. Hardin, Dec 28 2013

Status

approved