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A295230
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Numbers n such that there are precisely 2 groups of orders n and n + 1.
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9
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9, 21, 25, 38, 45, 57, 93, 105, 121, 165, 194, 201, 202, 205, 206, 218, 253, 261, 301, 325, 326, 357, 361, 381, 385, 422, 453, 477, 482, 538, 542, 554, 614, 626, 633, 662, 746, 758, 765, 801, 841, 861, 897, 921, 925, 934, 1005, 1017, 1045, 1046, 1081, 1094, 1113, 1126, 1137
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OFFSET
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1,1
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COMMENTS
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Equivalently, lower member of consecutive terms of A054395.
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LINKS
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FORMULA
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EXAMPLE
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MATHEMATICA
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Select[Range[1200], FiniteGroupCount[#] == 2 && FiniteGroupCount[# + 1] == 2 &] (* Jean-François Alcover, Dec 08 2017 *)
SequencePosition[FiniteGroupCount[Range[1200]], {2, 2}][[;; , 1]] (* Harvey P. Dale, Aug 18 2023 *)
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PROG
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(GAP) A295230 := Filtered([1..2014], n -> [NumberSmallGroups(n), NumberSmallGroups(n+1)]=[2, 2]);
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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