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 A327269 Smallest modulus of any integer n X n determinant with top row 1,2,...,n and rows nonzero and pairwise orthogonal 3
 1, 5, 42, 90, 990, 5733, 6720, 39168 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Also a(n) = A327267(p_1...p_n), with p_j = j-th prime, since p_1...p_n is the Heinz code for the multiset {1,2,3,...,n}. For more details see Pinner and Smyth link. LINKS Chris Pinner and Chris Smyth, Lattices of minimal index in Z^n having an orthogonal basis containing a given basis vector Christopher J. Smyth, List of n, a(n) and associated matrix, for n <= 8 EXAMPLE a(3)=42 since det([1,2,3],[1,-2,1],[4,1,-2]) = 42 and is the smallest positive determinant with top row [1,2,3] and all rows orthogonal. CROSSREFS Subsequence of A327267-- see comments; A327271 is similar, but determinant's top row is n 1's; A327272 is similar, but determinant's top row is 1,2,2^2,...,2^n. Sequence in context: A216610 A025173 A222474 * A266021 A062021 A241780 Adjacent sequences:  A327266 A327267 A327268 * A327270 A327271 A327272 KEYWORD nonn,more AUTHOR Christopher J. Smyth, Sep 02 2019 STATUS approved

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Last modified September 18 05:44 EDT 2020. Contains 337166 sequences. (Running on oeis4.)