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Search: id:A034268
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| A034268 |
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Least common multiple of {2^k - 1, k=1..n}. |
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+0
4
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| 1, 3, 21, 105, 3255, 9765, 1240155, 21082635, 1539032355, 16929355905, 34654391537535, 450507089987955, 3690103574091339405, 158674453685927594415, 23959842506575066756665
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OFFSET
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1,2
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FORMULA
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lcm(1, 3, 7, ..., 2^n - 1)
Product_{k=1..n} Phi_k(2), where Phi_n(2) is n-th cyclotomic polynomial at x=2(cf. A019320). - Vladeta Jovovic (vladeta(AT)eunet.rs), Jan 20 2002
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EXAMPLE
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a(3) = lcm(1,3,7) = 21
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CROSSREFS
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Cf. A051844.
Cf. A019320.
Sequence in context: A076207 A134057 A128281 this_sequence A140451 A054147 A043012
Adjacent sequences: A034265 A034266 A034267 this_sequence A034269 A034270 A034271
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KEYWORD
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nonn
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AUTHOR
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Jeffrey Shallit (shallit(AT)graceland.uwaterloo.ca), Apr 20 2000
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