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A324255
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Lesser of super amicable pair m < n defined by sigma(sigma(m)) = sigma(sigma(n)) = m + n.
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1
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23, 14999, 34673, 55373, 2056961, 2458187, 4586987, 5174363, 6204767, 15788453, 20699927, 22239647, 25748273, 43428947, 53636627, 74005637, 92626307, 132253139, 134131379, 158486747, 167677187, 183614987, 307412933, 385042487, 413859143, 418168343, 683772017
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OFFSET
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1,1
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COMMENTS
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The larger numbers in each pair are in A324256.
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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, n]], {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(n, ", ")); ); } \\ 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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