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Search: id:A052157
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| A052157 |
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Least positive integer r such that there exists an integer s, 0 <= s < r gcd(r-i, s-j) > 1 for all integers i, j with 0 <= i, j < n. |
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+0
1
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OFFSET
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0,1
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FORMULA
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a_n < e^{(1+o(1)) 2 n^2 log n}
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EXAMPLE
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a_1 = 2 because we can choose r = 2, s = 0; a_2 = 21 because we can choose r = 21, s = 15; a_3 = 1310 because we can choose r = 1310, s = 1276;...
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CROSSREFS
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Sequence in context: A019994 A015193 A022488 this_sequence A050204 A022470 A080815
Adjacent sequences: A052154 A052155 A052156 this_sequence A052158 A052159 A052160
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KEYWORD
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nonn,nice,bref,more
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AUTHOR
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Jeffrey Shallit (elvis(AT)graceland.uwaterloo.ca), Jan 25 2000
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EXTENSIONS
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By brute force search I know that a_4 > 410000. And also I know by constructing the pair (r, s) = (477742707, 172379781) that a_4 <= 477742707.
a(4) > 1,475,000 - Jud McCranie (j.mccranie(AT)comcast.net), Jan 26 2000
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