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A324256
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Larger of super amicable pair m < n defined by sigma(sigma(m)) = sigma(sigma(n)) = m + n.
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2
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37, 28201, 34687, 65587, 2089951, 4091797, 8340613, 8161477, 10124833, 18927067, 37179433, 37393633, 25855567, 64346413, 107160373, 95150203, 159440893, 238973101, 257658061, 277743397, 322210813, 256268149, 349883707, 578403913, 814865497, 752724457, 704710543
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OFFSET
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1,1
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COMMENTS
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The terms are ordered according to the their lesser counterparts (A324255).
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LINKS
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EXAMPLE
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(23, 37) are the first pair since sigma(sigma(23)) = sigma(sigma(37)) = 60 = 23 + 37.
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MATHEMATICA
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seq={}; s[n_]:=DivisorSigma[1, DivisorSigma[1, n]]-n; Do[m=s[n]; If[m>n && s[m]==n, AppendTo[seq, m]], {n, 1, 60000}]; seq
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PROG
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(PARI) f(n) = sigma(sigma(n)) - n;
lista(nn) = {for (n=1, nn, my(fn = f(n)); if ((fn > n) && (f(fn) == n), print1(fn, ", ")); ); } \\ Michel Marcus, Feb 20 2019
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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