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 A317140 Number of permutations of [2n+1] with exactly n increasing runs of length two. 3
 1, 4, 43, 906, 31493, 1629248, 117248463, 11190963430, 1367267690953, 208031951035452, 38563334673062963, 8554779137299629314, 2237467931691025532493, 681305299577272105281016, 238929711424864185326131543, 95603626135129502838914478558 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Alois P. Heinz, Table of n, a(n) for n = 0..242 FORMULA a(n) = A317139(2n+1) = A097592(2n+1,n). a(n) + n == 1 (mod 2). EXAMPLE a(1) = 4: 132, 213, 231, 312. CROSSREFS Bisection (odd part) of A317139. Cf. A097592. Sequence in context: A074702 A197717 A277456 * A152282 A153255 A015084 Adjacent sequences: A317137 A317138 A317139 * A317141 A317142 A317143 KEYWORD nonn AUTHOR Alois P. Heinz, Jul 22 2018 STATUS approved

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Last modified January 29 00:02 EST 2023. Contains 359905 sequences. (Running on oeis4.)