A234725 Number of (n+1) X (5+1) 0..7 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 7 (constant-stress 1 X 1 tilings).

74496, 168928, 360760, 1000264, 2557656, 8002936, 23194936, 78550072, 248588376, 891039928, 3005210680, 11247553144, 39802610136, 154128225976, 566417244856, 2254268472952, 8541311322456, 34760552342968, 135063296947000

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..52

Formula

Empirical: a(n) = 4*a(n-1) +137*a(n-2) -560*a(n-3) -8456*a(n-4) +35504*a(n-5) +310702*a(n-6) -1349320*a(n-7) -7561533*a(n-8) +34294092*a(n-9) +128206281*a(n-10) -615707400*a(n-11) -1548288698*a(n-12) +8040276992*a(n-13) +13333179376*a(n-14) -77453548480*a(n-15) -79946374816*a(n-16) +552146144704*a(n-17) +309222145232*a(n-18) -2893327015040*a(n-19) -567224779296*a(n-20) +10948880162304*a(n-21) -974085452928*a(n-22) -28950298675200*a(n-23) +9103597862400*a(n-24) +50436504576000*a(n-25) -24908850432000*a(n-26) -51674112000000*a(n-27) +32903055360000*a(n-28) +23410114560000*a(n-29) -17557585920000*a(n-30).

Example

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

Crossrefs

Column 5 of A234728.

Sequence in context: A079543 A033450 A033448 * A058415 A238521 A104846

Adjacent sequences: A234722 A234723 A234724 * A234726 A234727 A234728

Keyword

nonn

Author

R. H. Hardin, Dec 30 2013

Status

approved