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 A047182 Number of nonempty subsets of {1,2,...,n} in which exactly 1/2 of the elements are <= (n-2)/2. 1
 0, 0, 0, 3, 4, 14, 20, 55, 83, 209, 329, 791, 1286, 3002, 5004, 11439, 19447, 43757, 75581, 167959, 293929, 646645, 1144065, 2496143, 4457399, 9657699, 17383859, 37442159, 67863914, 145422674, 265182524, 565722719, 1037158319 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 LINKS Table of n, a(n) for n=1..33. FORMULA a(n) = C(n, [(n-2)/2]) - 1 = A037955(n) - 1. - Ralf Stephan, Mar 16 2004 CROSSREFS Sequence in context: A282684 A024863 A025107 * A080878 A110565 A332270 Adjacent sequences: A047179 A047180 A047181 * A047183 A047184 A047185 KEYWORD nonn AUTHOR Clark Kimberling STATUS approved

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Last modified December 2 12:48 EST 2023. Contains 367517 sequences. (Running on oeis4.)