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 A203820 Number of (n+1)X3 0..3 arrays with no 2X2 subblock having equal diagonal elements or equal antidiagonal elements 1
 1296, 27216, 571536, 12002256, 252047376, 5292994896, 111152892816, 2334210749136, 49018425731856, 1029386940368976, 21617125747748496, 453959640702718416, 9533152454757086736, 200196201549898821456 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 2 of A203826 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 1296*21^(n-1) EXAMPLE Some solutions for n=4 ..1..0..1....3..1..3....2..1..1....1..0..0....0..2..0....3..0..1....2..0..1 ..2..2..1....2..0..3....2..3..2....1..3..1....3..1..0....1..2..1....1..3..1 ..0..0..1....1..1..1....0..0..0....2..2..0....2..1..2....1..2..3....0..2..1 ..1..2..1....3..2..3....2..1..3....1..3..1....0..3..2....3..0..3....1..2..3 ..1..0..0....0..1..1....2..0..2....0..2..1....0..1..0....1..1..3....0..2..3 CROSSREFS Sequence in context: A223560 A016912 A330980 * A017056 A223596 A265471 Adjacent sequences: A203817 A203818 A203819 * A203821 A203822 A203823 KEYWORD nonn AUTHOR R. H. Hardin Jan 06 2012 STATUS approved

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Last modified September 29 16:58 EDT 2023. Contains 365773 sequences. (Running on oeis4.)