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A112822
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Least number k such that lcm{1,2,...,k}/denominator of harmonic number H(k) = 2n-1.
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14
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1, 6, 105, 44, 63, 33, 156, 20, 272, 343, 38272753, 11881, 100, 66, 822, 28861, 77
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OFFSET
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1,2
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COMMENTS
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First occurrence of 2n-1 in A110566.
Sequence continues: a(18)=?, 1332, 162, 2758521, 24649, 21, a(24)=?, 294, a(26)=?, 1166, 110, 126059, 201957, 3660, 37553041, 344929, 296341, a(35)=?, 25155299, a(37)=?, 500, 42
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LINKS
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MATHEMATICA
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a = h = 1; t = Table[0, {100}]; Do[a = LCM[a, n]; h = h + 1/n; b = a/Denominator[h]; If[b < 101 && t[[(b + 1)/2]] == 0, t[[(b + 1)/2]] = n], {n, 500000}]; t
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PROG
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(Python)
from fractions import Fraction
from sympy import lcm
k, l, h = 1, 1, Fraction(1, 1)
while l != h.denominator*(2*n-1):
k += 1
l = lcm(l, k)
h += Fraction(1, k)
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CROSSREFS
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Cf. A110566, A098464, A112813, A112814, A112815, A112816, A112817, A112818, A112819, A112820, A112821.
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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