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 A280311 Number of nX4 0..2 arrays with no element equal to more than one of its horizontal and vertical neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards. 1
 1, 222, 20274, 1047790, 43973846, 1638451216, 56602534187, 1855013487412, 58477471703834, 1789245480207404, 53466135036128845, 1567267054619722560, 45216089994262687510, 1287122022861142748302, 36222158292582837870301 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Column 4 of A280313. LINKS R. H. Hardin, Table of n, a(n) for n = 1..89 EXAMPLE Some solutions for n=3 ..0..1..2..0. .0..1..1..2. .0..1..0..2. .0..0..0..0. .0..0..1..1 ..2..1..2..1. .2..0..2..2. .2..1..1..2. .1..1..0..1. .1..0..2..0 ..1..1..0..0. .1..0..0..1. .1..1..2..0. .0..2..2..0. .0..2..2..0 CROSSREFS Cf. A280313. Sequence in context: A251059 A220230 A281696 * A268024 A267931 A268017 Adjacent sequences:  A280308 A280309 A280310 * A280312 A280313 A280314 KEYWORD nonn AUTHOR R. H. Hardin, Dec 31 2016 STATUS approved

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Last modified December 2 07:32 EST 2021. Contains 349437 sequences. (Running on oeis4.)