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 A319850 Number of distinct positive integers that can be obtained, starting with the initial interval partition (1, ..., n), by iteratively adding or multiplying together parts until only one part remains. 10
 1, 2, 5, 21, 94, 446, 2287, 12568, 78509 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS EXAMPLE The n-th row lists all integers that can be obtained starting with (1, ..., n):   1   2 3   5 6 7 8 9   9 10 11 12 13 14 15 16 17 18 19 20 21 24 25 26 27 28 30 32 36 MATHEMATICA ReplaceListRepeated[forms_, rerules_]:=Union[Flatten[FixedPointList[Function[pre, Union[Flatten[ReplaceList[#, rerules]&/@pre, 1]]], forms], 1]]; Table[Length[Select[ReplaceListRepeated[{Range[n]}, {{foe___, x_, mie___, y_, afe___}:>Sort[Append[{foe, mie, afe}, x+y]], {foe___, x_, mie___, y_, afe___}:>Sort[Append[{foe, mie, afe}, x*y]]}], Length[#]==1&]], {n, 6}] CROSSREFS Cf. A000041, A001055, A001970, A048249, A066739, A066815, A070960, A201163, A318948, A318949, A319841. Sequence in context: A152801 A062297 A047104 * A270597 A174080 A337283 Adjacent sequences:  A319847 A319848 A319849 * A319851 A319852 A319853 KEYWORD nonn,more AUTHOR Gus Wiseman, Sep 29 2018 STATUS approved

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Last modified September 27 10:28 EDT 2021. Contains 347689 sequences. (Running on oeis4.)