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 A251484 Number of (n+1) X (1+1) 0..3 arrays with no 2 X 2 subblock having the sum of its diagonal elements less than the minimum of its antidiagonal elements. 1
 236, 3456, 50576, 740096, 10830016, 158478336, 2319053056, 33935282176, 496583453696, 7266629615616, 106334404775936, 1556017884102656, 22769598050123776, 333193211119927296, 4875699416916361216 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 16*a(n-1) - 20*a(n-2). Empirical g.f.: 4*x*(59 - 80*x) / (1 - 16*x + 20*x^2). - Colin Barker, Nov 29 2018 EXAMPLE Some solutions for n=3: ..0..1....2..1....1..1....1..3....2..2....2..0....1..3....0..0....1..3....0..2 ..3..2....2..0....2..1....2..2....3..1....1..2....1..1....0..1....1..1....1..1 ..0..2....2..0....1..3....1..1....0..0....0..0....0..3....1..3....1..3....0..1 ..0..1....1..1....3..3....0..0....2..2....2..0....0..3....0..0....1..1....3..2 CROSSREFS Column 1 of A251491. Sequence in context: A334649 A233983 A251491 * A247475 A233166 A138820 Adjacent sequences:  A251481 A251482 A251483 * A251485 A251486 A251487 KEYWORD nonn AUTHOR R. H. Hardin, Dec 03 2014 STATUS approved

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Last modified December 1 16:44 EST 2021. Contains 349430 sequences. (Running on oeis4.)