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 A274970 Number of 2-stack pushall sortable permutations of length n. 1
 1, 1, 2, 6, 24, 120, 698, 4393, 28551, 187403, 1231517, 8080058, 52905865, 345820994 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS A 2-stack pushall sortable permutation is one that can be sorted by two stacks in series by pushing all elements to the stacks before writing any element to the output. A permutation of length n is 2-stack pushall sortable if and only if it can be sorted by a sequence of 3n operations represented by a pushall stack word of length 3n. LINKS Adeline Pierrot and Dominique Rossin, 2-stack pushall sortable permutations, arXiv:1303.4376 [cs.DM], 2013. CROSSREFS Cf. A263929 (permutations sortable with two stacks in series). Cf. A274969 (pushall stack words of length 3n). Sequence in context: A068200 A189847 A189284 * A177525 A177532 A242573 Adjacent sequences:  A274967 A274968 A274969 * A274971 A274972 A274973 KEYWORD nonn,more AUTHOR David Bevan, Jul 13 2016 EXTENSIONS a(11)-a(13) from Bert Dobbelaere, Dec 26 2018 STATUS approved

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Last modified August 7 19:57 EDT 2020. Contains 336279 sequences. (Running on oeis4.)