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 A290492 Maximal number of binary vectors of length n such that the unions (or bitwise ORs) of any 3 distinct vectors are all distinct. 0
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 OFFSET 0,2 COMMENTS Maximal number of subsets of an n-set such that the unions of any 3 distinct subsets are all distinct. The concatenation of these vectors produces a 3-separable matrix. a(13) >= 15. Here is a candidate solution: {1100100010000 0100010000011 0001101000001 0000000011001 1010000100001 0010100001010 0101000101000 0001000000000 0110001000100 0000110000100 0000001100010 1001000000110 0000000110100 0011010010000 1000011001000}. - Dmitry Kamenetsky, Sep 07 2017 REFERENCES Background: D.-Z. Du and F. K. Hwang, Combinatorial Group Testing and Its Applications, World Scientific, 2nd ed., 2000; see Chap. 7. LINKS Wikipedia, Disjunct Matrix EXAMPLE Here is a solution for n=12: {100000001100 000001010001 100101100000 010000110100 000110000101 011100000000 001000101001 000000000000 101010010000 001001000110 000100011010 000010100010 110000000011 010011001000}. CROSSREFS Cf. A054961. Sequence in context: A043318 A044915 A161951 * A191431 A191430 A011760 Adjacent sequences: A290489 A290490 A290491 * A290493 A290494 A290495 KEYWORD nonn,more AUTHOR Dmitry Kamenetsky, Aug 04 2017 STATUS approved

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Last modified March 28 23:19 EDT 2023. Contains 361596 sequences. (Running on oeis4.)