A234706 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 6 (constant-stress 1 X 1 tilings).

1730, 7154, 28170, 127586, 546362, 2630882, 11903466, 59901074, 281693210, 1465393634, 7088270730, 37835231666, 186909507002, 1018178950082, 5110859386026, 28298492397074, 143792918144090, 806722604366114

Offset

1,1

Links

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

Formula

Empirical: a(n) = 12*a(n-1) +159*a(n-2) -2412*a(n-3) -9452*a(n-4) +217248*a(n-5) +161262*a(n-6) -11578680*a(n-7) +10718427*a(n-8) +405901116*a(n-9) -824307633*a(n-10) -9828766476*a(n-11) +28650887914*a(n-12) +167599827384*a(n-13) -632763934044*a(n-14) -2003077953360*a(n-15) +9664372451624*a(n-16) +16138030431072*a(n-17) -105143721192576*a(n-18) -76625123046912*a(n-19) +819575849887488*a(n-20) +75093856109568*a(n-21) -4528143100320768*a(n-22) +1633754973450240*a(n-23) +17236678723430400*a(n-24) -11938042414080000*a(n-25) -42782336704512000*a(n-26) +40275310510080000*a(n-27) +62010467205120000*a(n-28) -70124998164480000*a(n-29) -39609913835520000*a(n-30) +50565847449600000*a(n-31).

Example

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

Crossrefs

Column 2 of A234712.

Sequence in context: A339878 A258166 A130876 * A211853 A252454 A256807

Adjacent sequences: A234703 A234704 A234705 * A234707 A234708 A234709

Keyword

nonn

Author

R. H. Hardin, Dec 29 2013

Status

approved