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 A326898 Number of unlabeled topologies with up to n points. 5
 1, 2, 5, 14, 47, 186, 904, 5439, 41418, 404501, 5122188, 84623842, 1828876351, 51701216248, 1908493827243, 91755916071736, 5729050033597431 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Table of n, a(n) for n=0..16. EXAMPLE Non-isomorphic representatives of the a(0) = 1 through a(3) = 14 topologies: {} {} {} {} {}{1} {}{1} {}{1} {}{12} {}{12} {}{2}{12} {}{123} {}{1}{2}{12} {}{2}{12} {}{3}{123} {}{23}{123} {}{1}{2}{12} {}{1}{23}{123} {}{3}{23}{123} {}{2}{3}{23}{123} {}{3}{13}{23}{123} {}{2}{3}{13}{23}{123} {}{1}{2}{3}{12}{13}{23}{123} CROSSREFS Partial sums of A001930. The labeled version is A326878. Cf. A000612, A000798, A003180, A108800, A193675, A306445, A326867, A326882. Sequence in context: A317784 A096402 A007268 * A109156 A143918 A129867 Adjacent sequences: A326895 A326896 A326897 * A326899 A326900 A326901 KEYWORD nonn AUTHOR Gus Wiseman, Aug 02 2019 STATUS approved

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Last modified June 21 13:19 EDT 2024. Contains 373544 sequences. (Running on oeis4.)