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A002953
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Larger of unitary amicable pair.
(Formerly M5389)
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5
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126, 1260, 22302, 40446, 49308, 64530, 73962, 168730, 223020, 286500, 242730, 429750, 365700, 548550, 618570, 827700, 739620, 827652, 932100, 1241550, 1099390, 1291050, 1292570, 1241478, 1398150, 1621500, 1669150, 1598470, 1654212
(list;
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history;
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OFFSET
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1,1
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REFERENCES
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P. Hagis, Jr., Unitary amicable numbers, Math. Comp., 25 (1971), 915-918.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
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T. D. Noe, Table of n, a(n) for n = 1..7896 (from Pedersen's website)
J. M. Pedersen, Known Unitary Amicable Pairs
J. O. M. Pedersen, Tables of Aliquot Cycles
Eric Weisstein's World of Mathematics, Unitary Amicable Pair
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MATHEMATICA
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uDivisors[n_] := Select[Divisors[n], # < n && GCD[#, n/#] == 1 & ]; mate[n_] := If[m = Total[uDivisors[n]]; n == Total[uDivisors[m]], m, 0]; Reap[Do[If[n < (m = mate[n]), Print[m]; Sow[m]], {n, 2, 2000000}]][[2, 1]] (* Jean-François Alcover, Jun 12 2012 *)
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CROSSREFS
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Cf. A002952, A063991, A111904.
Sequence in context: A154093 A172139 A194717 * A216588 A027805 A027814
Adjacent sequences: A002950 A002951 A002952 * A002954 A002955 A002956
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KEYWORD
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nonn,nice
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AUTHOR
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N. J. A. Sloane; extended Nov 24 2005
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STATUS
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approved
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