A235181 - OEIS

A235181

Number of (n+1) X (3+1) 0..5 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).

576, 1400, 3240, 8224, 19952, 52328, 131120, 352000, 903544, 2468016, 6458176, 17881160, 47552704, 133129216, 359039112, 1014613904, 2770351216, 7892016840, 21785349232, 62495913056, 174180409272, 502718703312, 1412888840448

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OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) +44*a(n-2) -133*a(n-3) -842*a(n-4) +2563*a(n-5) +9221*a(n-6) -28202*a(n-7) -64059*a(n-8) +195733*a(n-9) +296446*a(n-10) -893437*a(n-11) -937956*a(n-12) +2714749*a(n-13) +2064161*a(n-14) -5442684*a(n-15) -3205526*a(n-16) +7001040*a(n-17) +3522128*a(n-18) -5502080*a(n-19) -2622832*a(n-20) +2452848*a(n-21) +1173648*a(n-22) -555264*a(n-23) -271584*a(n-24) +48384*a(n-25) +24192*a(n-26).

EXAMPLE

Some solutions for n=4:

0 3 0 3 2 3 2 3 5 1 4 1 3 5 1 4 2 4 2 3

4 2 4 2 4 0 4 0 3 4 2 4 5 2 3 1 4 1 4 0

2 5 2 5 3 4 3 4 4 0 3 0 2 4 0 3 2 4 2 3

3 1 3 1 4 0 4 0 3 4 2 4 4 1 2 0 5 2 5 1

0 3 0 3 1 2 1 2 4 0 3 0 3 5 1 4 3 5 3 4

CROSSREFS

Column 3 of A235186.

Sequence in context: A069266 A060678 A254848 * A268773 A250789 A137484

Adjacent sequences: A235178 A235179 A235180 * A235182 A235183 A235184

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 04 2014

STATUS

approved