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 A280902 T(n,k)=Number of nXk 0..2 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards. 11
 0, 0, 0, 0, 1, 0, 1, 10, 9, 0, 2, 213, 646, 124, 0, 9, 2292, 22568, 22632, 1464, 0, 34, 21762, 492490, 1451655, 610448, 15768, 0, 124, 184076, 9426050, 65348136, 75809243, 14262832, 159920, 0, 432, 1457827, 162640161, 2571528867, 7083739466 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,8 COMMENTS Table starts .0........0............0...............1..................2...................9 .0........1...........10.............213...............2292...............21762 .0........9..........646...........22568.............492490.............9426050 .0......124........22632.........1451655...........65348136..........2571528867 .0.....1464.......610448........75809243.........7083739466........574982226478 .0....15768.....14262832......3521886844.......684011230518.....114677717497532 .0...159920....304584096....151803173493.....61277484218852...21239418911643829 .0..1554304...6117000704...6210239609889...5208435552362140.3734730743379447607 .0.14632704.117496694272.244458357395448.425813044528570428 LINKS R. H. Hardin, Table of n, a(n) for n = 1..96 FORMULA Empirical for column k: k=1: a(n) = a(n-1) k=2: [order 6] for n>8 k=3: [order 6] for n>8 k=4: [order 12] for n>14 k=5: [order 24] for n>27 Empirical for row n: n=1: a(n) = 6*a(n-1) -6*a(n-2) -16*a(n-3) +12*a(n-4) +24*a(n-5) +8*a(n-6) for n>10 n=2: [order 15] for n>17 n=3: [order 54] for n>60 EXAMPLE Some solutions for n=3 k=4 ..0..0..1..2. .0..0..1..0. .0..1..0..0. .0..1..0..2. .0..1..2..0 ..1..1..2..1. .2..1..0..0. .2..1..0..2. .1..2..2..0. .1..1..1..2 ..0..0..1..1. .1..0..2..0. .1..0..2..0. .1..1..1..2. .2..2..0..1 CROSSREFS Row 1 is A280309. Sequence in context: A317813 A038310 A318421 * A118768 A318255 A008956 Adjacent sequences:  A280899 A280900 A280901 * A280903 A280904 A280905 KEYWORD nonn,tabl AUTHOR R. H. Hardin, Jan 10 2017 STATUS approved

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Last modified June 28 02:57 EDT 2022. Contains 354903 sequences. (Running on oeis4.)