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 A324256 Larger of super amicable pair m < n defined by sigma(sigma(m)) = sigma(sigma(n)) = m + n. 2
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The terms are ordered according to the their lesser counterparts (A324255). Analogous to A002046 as A019279 is analogous to A000396. LINKS EXAMPLE (23, 37) are the first pair since sigma(sigma(23)) = sigma(sigma(37)) = 60 = 23 + 37. MATHEMATICA 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 PROG (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 CROSSREFS Cf. A000203, A000396, A002046, A019279, A045614 (unitary analog), A051027, A324255. Sequence in context: A202794 A129054 A129053 * A096349 A015061 A015037 Adjacent sequences:  A324253 A324254 A324255 * A324257 A324258 A324259 KEYWORD nonn AUTHOR Amiram Eldar, Feb 19 2019 STATUS approved

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Last modified November 29 04:04 EST 2021. Contains 349416 sequences. (Running on oeis4.)