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 A320371 T(n,k)=Number of nXk 0..1 arrays with every element unequal to 0, 1, 2, 3 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 7
 1, 2, 2, 4, 8, 4, 8, 32, 32, 8, 16, 128, 228, 128, 16, 32, 512, 1612, 1612, 512, 32, 64, 2048, 11396, 19840, 11396, 2048, 64, 128, 8192, 80568, 245060, 245060, 80568, 8192, 128, 256, 32768, 569608, 3027408, 5304988, 3027408, 569608, 32768, 256, 512, 131072 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Table starts ...1......2........4..........8............16..............32................64 ...2......8.......32........128...........512............2048..............8192 ...4.....32......228.......1612.........11396...........80568............569608 ...8....128.....1612......19840........245060.........3027408..........37398884 ..16....512....11396.....245060.......5304988.......114844160........2486026176 ..32...2048....80568....3027408.....114844160......4358279956......165355751224 ..64...8192...569608...37398884....2486026176....165355751224....10993944343316 .128..32768..4027076..462004160...53815748216...6274017360108...731023916987668 .256.131072.28471056.5707334644.1164968680976.238053099337172.48608312646628816 LINKS R. H. Hardin, Table of n, a(n) for n = 1..220 FORMULA Empirical for column k: k=1: a(n) = 2*a(n-1) k=2: a(n) = 4*a(n-1) k=3: a(n) = 8*a(n-1) -7*a(n-2) +3*a(n-3) k=4: [order 9] k=5: [order 25] for n>26 k=6: [order 70] for n>73 EXAMPLE Some solutions for n=5 k=4 ..0..0..0..0. .0..0..0..1. .0..0..0..0. .0..0..0..1. .0..0..1..0 ..0..0..1..1. .1..1..0..0. .1..1..1..1. .1..1..1..0. .0..0..0..1 ..1..1..0..0. .1..1..0..1. .0..1..1..1. .1..1..0..0. .0..0..1..1 ..1..0..0..0. .0..0..0..0. .0..0..0..1. .0..1..0..0. .0..1..0..1 ..1..1..1..0. .0..1..0..1. .1..0..0..0. .1..0..1..1. .1..0..0..0 CROSSREFS Column 1 is A000079(n-1). Column 2 is A004171(n-1). Sequence in context: A299740 A316815 A299661 * A317565 A302741 A300215 Adjacent sequences: A320368 A320369 A320370 * A320372 A320373 A320374 KEYWORD nonn,tabl AUTHOR R. H. Hardin, Oct 11 2018 STATUS approved

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Last modified September 22 10:28 EDT 2023. Contains 365520 sequences. (Running on oeis4.)