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 A295531 T(n,k)=Number of nXk 0..1 arrays with each 1 horizontally or vertically adjacent to 1, 2 or 4 1s. 8
 1, 2, 2, 4, 10, 4, 7, 29, 29, 7, 12, 87, 147, 87, 12, 21, 280, 774, 774, 280, 21, 37, 876, 4080, 7071, 4080, 876, 37, 65, 2735, 21489, 64189, 64189, 21489, 2735, 65, 114, 8583, 113466, 588529, 1012315, 588529, 113466, 8583, 114, 200, 26900, 598374, 5400933 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Table starts ...1.....2.......4.........7..........12............21...............37 ...2....10......29........87.........280...........876.............2735 ...4....29.....147.......774........4080.........21489...........113466 ...7....87.....774......7071.......64189........588529..........5400933 ..12...280....4080.....64189.....1012315......16031147........253594307 ..21...876...21489....588529....16031147.....437241277......11938414614 ..37..2735..113466...5400933...253594307...11938414614.....563330031268 ..65..8583..598374..49414072..4003959566..325438086413...26515589323171 .114.26900.3155426.452274232.63279327977.8875686431050.1248681784524804 LINKS R. H. Hardin, Table of n, a(n) for n = 1..241 FORMULA Empirical for column k: k=1: a(n) = 2*a(n-1) -a(n-2) +a(n-3) k=2: a(n) = 2*a(n-1) +2*a(n-2) +5*a(n-3) -a(n-5) -a(n-6) k=3: [order 18] k=4: [order 45] EXAMPLE Some solutions for n=5 k=4 ..0..1..1..1. .1..1..0..1. .0..0..1..1. .1..1..1..0. .0..1..1..0 ..0..1..0..1. .1..0..0..1. .0..0..0..1. .0..0..0..1. .0..0..0..0 ..1..1..0..0. .0..1..1..0. .1..0..0..1. .1..1..0..1. .1..1..0..0 ..0..0..1..1. .1..1..1..0. .1..0..0..0. .1..0..0..1. .0..1..0..1 ..0..0..1..1. .1..1..0..0. .0..1..1..0. .1..1..1..0. .0..1..1..1 CROSSREFS Column 1 is A005251(n+2). Sequence in context: A296386 A296643 A295040 * A220259 A220323 A295416 Adjacent sequences: A295528 A295529 A295530 * A295532 A295533 A295534 KEYWORD nonn,tabl AUTHOR R. H. Hardin, Nov 23 2017 STATUS approved

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Last modified March 2 15:53 EST 2024. Contains 370494 sequences. (Running on oeis4.)