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 A203980 Number of (n+1) X 5 0..2 arrays with no 2 X 2 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..2 introduced in row major order. 1
 384, 5184, 69984, 956448, 13071456, 178855776, 2447270496, 33489653472, 458288894304, 6271519652064, 85823503984224, 1174465206026208, 16072153386090336, 219941927082883296, 3009830115907061856 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 4 of A203984. LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 15*a(n-1) - 270*a(n-3) + 324*a(n-4). Empirical g.f.: 96*x*(4 - 6*x - 81*x^2 + 108*x^3) / ((1 - 15*x + 18*x^2)*(1 - 18*x^2)). - Colin Barker, Jun 06 2018 EXAMPLE Some solutions for n=4: ..0..1..1..2..0....0..1..1..1..1....0..1..1..1..1....0..1..2..1..2 ..2..2..0..2..0....2..2..2..2..0....2..2..2..2..0....2..1..2..1..2 ..0..1..1..2..1....1..0..0..1..1....1..0..1..1..0....0..0..2..0..2 ..0..2..0..2..0....2..2..2..2..2....1..0..2..2..2....2..1..1..1..1 ..0..1..0..1..0....0..1..0..1..0....1..0..1..0..1....0..0..0..0..2 CROSSREFS Cf. A203984. Sequence in context: A252899 A183686 A134241 * A061403 A281656 A128967 Adjacent sequences:  A203977 A203978 A203979 * A203981 A203982 A203983 KEYWORD nonn AUTHOR R. H. Hardin, Jan 09 2012 STATUS approved

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Last modified December 4 11:50 EST 2021. Contains 349486 sequences. (Running on oeis4.)