A235315 Number of (n+1) X (4+1) 0..6 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 7 (constant-stress 1 X 1 tilings).

3920, 8392, 16352, 40144, 89600, 241600, 598976, 1723456, 4616960, 13917952, 39447872, 123109504, 363776000, 1165742080, 3555169856, 11629123456, 36344940800, 120802796032, 384900713792, 1295327764864, 4190699379200

Offset

1,1

Comments

Column 4 of A235319.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +47*a(n-2) -200*a(n-3) -901*a(n-4) +4204*a(n-5) +8957*a(n-6) -48440*a(n-7) -47194*a(n-8) +334096*a(n-9) +101948*a(n-10) -1410080*a(n-11) +170136*a(n-12) +3549696*a(n-13) -1446912*a(n-14) -4861440*a(n-15) +2954880*a(n-16) +2764800*a(n-17) -2073600*a(n-18).

Example

Some solutions for n=4:
  2 3 1 5 1     1 6 0 4 1     1 6 2 5 3     1 5 3 4 2
  6 0 5 2 5     6 4 5 2 6     4 2 5 1 6     4 1 6 0 5
  3 4 2 6 2     1 6 0 4 1     1 6 2 5 3     2 6 4 5 3
  6 0 5 2 5     6 4 5 2 6     3 1 4 0 5     4 1 6 0 5
  2 3 1 5 1     1 6 0 4 1     1 6 2 5 3     1 5 3 4 2

Crossrefs

Sequence in context: A209732 A221239 A136459 * A229642 A266060 A034283

Adjacent sequences: A235312 A235313 A235314 * A235316 A235317 A235318

Keyword

nonn

Author

R. H. Hardin, Jan 05 2014

Status

approved