A325848 - OEIS

A325848

Larger of exponentially-odd amicable numbers pair: numbers m < k such that m = s(k) and k = s(m), where s(k) is the sum of proper exponential-odd divisors of k.

378, 4584, 16632, 16728, 64032, 76704, 179118, 168730, 225096, 256338, 266568, 391656, 401952, 387720, 393528, 593952, 788448, 781728, 897888, 1052088, 1099390, 1292570, 1346598, 1598470, 2062570, 1863918, 2099424, 1940856, 2223720, 2429030, 2980056, 3336984

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OFFSET

1,1

COMMENTS

The terms are ordered according to their lesser counterparts (A325847).

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..789 (terms with lesser counterparts below 10^10)

MATHEMATICA

f[e_] := If[OddQ[e], e + 2, e + 1]; fun[p_, e_] := 1 + (p^f[e] - p)/(p^2 - 1); a[1] = 1; a[n_] := Times @@ (fun @@@ (fct = FactorInteger[n])) - If[AllTrue[fct[[;; , 2]], OddQ], n, 0]; s = {}; Do[m = a[n]; If[m > n && a[m] == n, AppendTo[s, m]], {n, 1, 10^5}]; s

CROSSREFS

Cf. A033289, A033634, A268335, A325847.

Sequence in context: A047632 A033699 A235544 * A248915 A225839 A221803

Adjacent sequences: A325845 A325846 A325847 * A325849 A325850 A325851

KEYWORD

nonn

AUTHOR

Amiram Eldar, Sep 07 2019

STATUS

approved