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A120267
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Numerator of Sum_{k=1..n} n^k/k!.
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6
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1, 4, 12, 100, 1085, 1218, 47201, 556088, 10659753, 7281020, 62927202701, 7217988, 60718623181177, 595952851172, 13324959230295, 247016251998448, 28505095507110827053, 549689328228186, 320305941258100632731917
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OFFSET
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1,2
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COMMENTS
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Apparently, the three sequences T_1(n) = Sum_{k=1..n} n^(k-1)/k!, T_2(n) = Sum_{k=0..n} n^k/k!, and T_3(n) = Sum_{k=1..n} n^k/k!, with numerators in A119029, A120266, and A120267, respectively, have the same denominators, listed in A214401. This, however, is not immediately obvious. - Petros Hadjicostas, May 12 2020
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LINKS
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FORMULA
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a(n) = numerator(Sum_{k=1..n} n^k/k!).
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EXAMPLE
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The first few fractions are 1, 4, 12, 100/3, 1085/12, 1218/5, 47201/72, 556088/315, 10659753/2240, 7281020/567, ... = A120267/A214401. - Petros Hadjicostas, May 12 2020
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MATHEMATICA
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Numerator[Table[Sum[n^k/k!, {k, 1, n}], {n, 1, 30}]]
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CROSSREFS
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KEYWORD
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frac,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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