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A227057
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Number of nX3 -2..2 arrays of 2X2 subblock diagonal sums minus antidiagonal sums for some (n+1)X4 binary array with rows and columns of the latter in lexicographically nondecreasing order
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1
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20, 124, 643, 2934, 11810, 42295, 136553, 402898, 1099681, 2805516, 6748051, 15412421, 33626114, 70430760, 142218700, 277853319, 526833214, 972034792, 1749218167, 3076360168, 5297051430, 8943742393, 14828643583, 24172697248
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = (1/1307674368000)*n^15 + (1/10897286400)*n^14 + (47/9340531200)*n^13 + (79/479001600)*n^12 + (25931/7185024000)*n^11 + (347/6220800)*n^10 + (143197/228614400)*n^9 + (1567309/304819200)*n^8 + (5780059/186624000)*n^7 + (244579/1741824)*n^6 + (370033369/718502400)*n^5 + (25976963/17107200)*n^4 + (4033604297/1135134000)*n^3 + (958946909/151351200)*n^2 + (55255/8008)*n + 1
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EXAMPLE
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Some solutions for n=3
..0..1..0....0..0..0....0..1.-1....0..1.-2....0.-2..1....1..0..0....0..1.-1
..1.-1..0....0..0..1....1.-1..0....1.-2..1....0..0..0...-2..1..0....1.-1.-1
.-2..1..0....0..1.-2...-1.-1..0...-1..0..0....0..0..0....0..0..0...-2..0..1
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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