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 A183430 One third the number of n X 2 0..3 arrays with no element equal to its row sum plus its column sum mod 4. 1
 4, 27, 244, 2187, 19684, 177147, 1594324, 14348907, 129140164, 1162261467, 10460353204, 94143178827, 847288609444, 7625597484987, 68630377364884, 617673396283947, 5559060566555524, 50031545098999707, 450283905890997364 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 2 of A183433. LINKS R. H. Hardin, Table of n, a(n) for n = 1..171 FORMULA Empirical: a(n) = 9*a(n-1) + a(n-2) - 9*a(n-3). Conjectures from Colin Barker, Mar 29 2018: (Start) G.f.: x*(4 - 9*x - 3*x^2) / ((1 - x)*(1 + x)*(1 - 9*x)). a(n) = 9^n / 3 for n even. a(n) = (6+2*9^n) / 6 for n odd. (End) EXAMPLE Some solutions for 3 X 2: ..1..2....2..0....3..1....2..2....1..3....3..0....0..1....0..2....3..3....1..1 ..1..2....3..0....3..0....2..2....2..2....2..0....3..1....1..3....3..0....0..1 ..3..0....2..0....3..1....1..1....0..0....1..0....3..0....2..0....1..3....1..3 CROSSREFS Cf. A183433. Sequence in context: A181146 A303559 A161120 * A212559 A265268 A121063 Adjacent sequences: A183427 A183428 A183429 * A183431 A183432 A183433 KEYWORD nonn AUTHOR R. H. Hardin, Jan 04 2011 STATUS approved

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Last modified December 7 11:43 EST 2022. Contains 358656 sequences. (Running on oeis4.)