A235206 Number of (n+1) X (2+1) 0..7 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).

1172, 4616, 18444, 76112, 319156, 1374400, 5998924, 26765648, 120643572, 553515168, 2557495628, 11985104432, 56413124340, 268564680000, 1281524215500, 6172279073168, 29750350541044, 144526879218144, 701822038872140

Offset

1,1

Links

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

Formula

Empirical: a(n) = 15*a(n-1) +23*a(n-2) -1373*a(n-3) +3547*a(n-4) +50847*a(n-5) -236177*a(n-6) -957405*a(n-7) +6739749*a(n-8) +8784137*a(n-9) -112122375*a(n-10) -8734283*a(n-11) +1205207433*a(n-12) -682793243*a(n-13) -8845512699*a(n-14) +8015164257*a(n-15) +45997463512*a(n-16) -47860413548*a(n-17) -173398534628*a(n-18) +175140255652*a(n-19) +476432770592*a(n-20) -402722060848*a(n-21) -936013467040*a(n-22) +551524974720*a(n-23) +1245278007168*a(n-24) -366681768960*a(n-25) -999476834304*a(n-26) +6506053632*a(n-27) +362586931200*a(n-28) +89712230400*a(n-29).

Example

Some solutions for n=4:
  0 7 0   7 3 4   2 0 1   0 7 1   6 3 5   0 4 5   4 5 6
  2 4 2   5 6 2   3 6 2   3 5 4   2 4 1   1 0 6   5 1 7
  3 0 3   7 3 4   6 4 5   6 3 7   5 2 4   2 6 7   4 5 6
  5 7 5   3 4 0   2 5 1   4 6 5   3 5 2   6 5 1   0 6 2
  6 3 6   0 6 7   3 1 2   6 3 7   6 3 5   7 1 2   2 3 4

Crossrefs

Column 2 of A235212.

Sequence in context: A230946 A225234 A253508 * A302230 A302673 A230706

Adjacent sequences: A235203 A235204 A235205 * A235207 A235208 A235209

Keyword

nonn

Author

R. H. Hardin, Jan 04 2014

Status

approved