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 A270118 T(n,k)=Number of nXk 0..7 arrays with some element plus some horizontally or vertically adjacent neighbor totalling seven exactly once. 9
 0, 8, 8, 112, 1344, 112, 1176, 100800, 100800, 1176, 10976, 6183744, 45440640, 6183744, 10976, 96040, 345422784, 16972694928, 16972694928, 345422784, 96040, 806736, 18272616768, 5795977666752, 38799000374400, 5795977666752 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Table starts .......0..............8...................112........................1176 .......8...........1344................100800.....................6183744 .....112.........100800..............45440640.................16972694928 ....1176........6183744...........16972694928..............38799000374400 ...10976......345422784.........5795977666752...........81224231406183600 ...96040....18272616768......1877723928063648.......161437591343857507392 ..806736...932758314432....587581295287557312....310047482243688075320784 .6588344.46431146637120.179399371883007424176.581128015182716709115556736 LINKS R. H. Hardin, Table of n, a(n) for n = 1..112 FORMULA Empirical for column k: k=1: a(n) = 14*a(n-1) -49*a(n-2) k=2: a(n) = 86*a(n-1) -1849*a(n-2) for n>3 k=3: a(n) = 540*a(n-1) -75994*a(n-2) +835380*a(n-3) -2393209*a(n-4) for n>5 k=4: [order 6] for n>7 k=5: [order 14] for n>15 k=6: [order 26] for n>27 EXAMPLE Some solutions for n=2 k=4 ..0..0..1..6. .4..4..6..3. .4..0..1..1. .4..4..5..0. .0..0..0..5 ..0..2..2..0. .0..1..5..4. .0..5..7..6. .0..7..5..1. .4..3..1..5 CROSSREFS Sequence in context: A228071 A192386 A119932 * A270150 A065241 A255006 Adjacent sequences:  A270115 A270116 A270117 * A270119 A270120 A270121 KEYWORD nonn,tabl AUTHOR R. H. Hardin, Mar 11 2016 STATUS approved

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Last modified April 14 11:04 EDT 2021. Contains 342949 sequences. (Running on oeis4.)