A234818 Number of (n+1) X (3+1) 0..6 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 6 (constant-stress 1 X 1 tilings).

2380, 6282, 15224, 47136, 131704, 443220, 1352816, 4791948, 15484360, 56779452, 190677584, 716514876, 2473383304, 9461029980, 33344399696, 129230455548, 462955104520, 1811799391452, 6576906075344, 25926079006716, 95144821863304

Offset

1,1

Links

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

Formula

Empirical: a(n) = 8*a(n-1) +60*a(n-2) -620*a(n-3) -1210*a(n-4) +20740*a(n-5) +1580*a(n-6) -392180*a(n-7) +353267*a(n-8) +4606324*a(n-9) -7135240*a(n-10) -34677440*a(n-11) +72387960*a(n-12) +165390560*a(n-13) -443380480*a(n-14) -464032320*a(n-15) +1696321584*a(n-16) +566607168*a(n-17) -3948347520*a(n-18) +465384960*a(n-19) +5084985600*a(n-20) -2142028800*a(n-21) -2757888000*a(n-22) +1741824000*a(n-23).

Example

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

Crossrefs

Column 3 of A234823.

Sequence in context: A255800 A252469 A252420 * A107530 A020394 A251649

Adjacent sequences: A234815 A234816 A234817 * A234819 A234820 A234821

Keyword

nonn

Author

R. H. Hardin, Dec 31 2013

Status

approved