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 A230739 T(n,k)=Number of (n+3)X(k+3) 0..2 black square subarrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 3, and upper left element zero 6
 2, 8, 8, 30, 66, 30, 102, 244, 244, 102, 348, 2016, 2106, 2016, 348, 1172, 6576, 16536, 16536, 6576, 1172, 3956, 54138, 130446, 320970, 130446, 54138, 3956, 13326, 173428, 1025430, 2382398, 2382398, 1025430, 173428, 13326, 44916, 1427040, 8053490 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Table starts .....2.......8.......30........102..........348...........1172.............3956 .....8......66......244.......2016.........6576..........54138...........173428 ....30.....244.....2106......16536.......130446........1025430..........8053490 ...102....2016....16536.....320970......2382398.......46599682........342031378 ...348....6576...130446....2382398.....43853402......801845362......14669811856 ..1172...54138..1025430...46599682....801845362....36695929036.....625553036008 ..3956..173428..8053490..342031378..14669811856...625553036008...26681634560690 .13326.1427040.63237238.6692078688.268320990890.28644012159382.1137681116923966 LINKS R. H. Hardin, Table of n, a(n) for n = 1..199 FORMULA Empirical for column k: k=1: a(n) = 3*a(n-1) +3*a(n-2) -6*a(n-3) +a(n-5) k=2: a(n) = 31*a(n-2) -126*a(n-4) +42*a(n-6) +79*a(n-8) -a(n-10) +8*a(n-12) k=3: [order 22] k=4: [order 50] EXAMPLE Some solutions for n=3 k=4 ..x..0..x..0..x..2..x....x..0..x..2..x..2..x....x..0..x..0..x..1..x ..1..x..1..x..1..x..0....2..x..1..x..0..x..1....1..x..1..x..2..x..0 ..x..2..x..0..x..1..x....x..0..x..1..x..1..x....x..2..x..0..x..2..x ..1..x..0..x..2..x..0....1..x..0..x..2..x..0....1..x..0..x..2..x..0 ..x..2..x..1..x..1..x....x..2..x..0..x..2..x....x..2..x..1..x..1..x ..1..x..1..x..0..x..0....1..x..2..x..1..x..1....1..x..0..x..0..x..0 CROSSREFS Column 1 is A230701 Column 3 is A230703 Column 5 is A230705 Column 7 is A230707 Sequence in context: A250313 A180825 A230708 * A227326 A064231 A181130 Adjacent sequences:  A230736 A230737 A230738 * A230740 A230741 A230742 KEYWORD nonn,tabl AUTHOR R. H. Hardin, Oct 28 2013 STATUS approved

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Last modified November 16 00:11 EST 2018. Contains 317252 sequences. (Running on oeis4.)