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 A291188 Number of inequivalent 2 X n Sudoku grids ((2*n) X (2*n) grids divided into 2 X n boxes). 1
 2, 49, 1673187, 4743933602050718 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,1 COMMENTS We regard two grids as inequivalent if one cannot be transformed into another by some sequence of symmetries, or by relabelling. For the 2 X 3 Sudoku grids case the allowed equivalences are (see link to Jarvis): - relabeling entries; reflection; rotation; - permutation of blocks of columns 1-2, 3-4 and 5-6; - permutation of blocks of rows 1-3 and 4-6; - permutation of columns 1-2; - permutation of columns 3-4; - permutation of columns 5-6; - permutation of rows 1-3; - permutation of rows 4-6. LINKS Frazer Jarvis, Sudoku enumeration problems Jordy Vanpoucke, Mutually orthogonal latin squares and their generalizations EXAMPLE a(2) = 2: 12|34  12|34 34|12  34|12 --+--  --+-- 21|43  23|41 43|21  41|23 -------------------------------- An example of 2 X 3 Sudoku grids: 14|25|36 35|16|24 26|34|15 --+--+-- 41|52|63 52|63|41 63|41|52 CROSSREFS Cf. A109741, A291187. Sequence in context: A269839 A088067 A145676 * A225795 A027619 A076267 Adjacent sequences:  A291185 A291186 A291187 * A291189 A291190 A291191 KEYWORD nonn,more AUTHOR Seiichi Manyama, Aug 19 2017 STATUS approved

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Last modified October 14 08:54 EDT 2019. Contains 327995 sequences. (Running on oeis4.)