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 A331708 Number of nonnegative integer matrices with distinct nonzero rows, total sum n, distinct columns with equals sums and columns in decreasing lexicographic order. 1
 1, 2, 4, 10, 6, 100, 14, 832, 1928, 9280, 66, 409928, 134, 3138847, 32173339, 134531629, 618, 9353244335, 1178, 183394485615, 2395983801112, 2311773448717, 4758, 1479147860804022, 311353753955807, 3599356750729620, 613047176698674761, 1842753685676233794, 30462 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The condition that the columns be in decreasing order is equivalent to considering nonequivalent matrices with distinct columns up to permutation of columns. LINKS FORMULA a(n) = Sum_{d|n} A331570(n/d, d). EXAMPLE The a(4) = 10 matrices are:   [1 0 0 0]  [1 1]  [1 0]  [1 0]   [0 1 0 0]  [1 0]  [1 1]  [0 1]   [0 0 1 0]  [0 1]  [0 1]  [1 1]   [0 0 0 1] .   [2 1]  [2 0]  [1 0]  [3]  [1]  [4]   [0 1]  [0 2]  [1 2]  [1]  [3] CROSSREFS Cf. A331570. Sequence in context: A159585 A130334 A320537 * A227289 A200742 A178729 Adjacent sequences:  A331705 A331706 A331707 * A331709 A331710 A331711 KEYWORD nonn AUTHOR Andrew Howroyd, Jan 25 2020 STATUS approved

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Last modified September 22 03:20 EDT 2021. Contains 347605 sequences. (Running on oeis4.)