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 A323330 Larger of amicable pair m < n defined by t(n) = m and t(m) = n where t(n) = psi(n) - n and psi(n) = A001615(n) is the Dedekind psi function. 4

%I #14 Jul 23 2019 11:44:07

%S 1550,3100,4790,6200,7750,9580,12400,12922,15500,15290,19160,20330,

%T 23950,24800,25844,31000,30580,38320,38750,40660,47900,49600,51688,

%U 62000,61160,76640,77500,82150,81320,76450,95800,90454,99200,103376,101650,119750,124000,122320

%N Larger of amicable pair m < n defined by t(n) = m and t(m) = n where t(n) = psi(n) - n and psi(n) = A001615(n) is the Dedekind psi function.

%C The terms are ordered according to the order of their lesser counterparts (A323329).

%H Amiram Eldar, <a href="/A323330/b323330.txt">Table of n, a(n) for n = 1..1000</a>

%t psi[n_] := n*Times@@(1+1/Transpose[FactorInteger[n]][[1]]); t[n_]:= psi[n] - n; s={}; Do[n=t[m]; If[n>m && t[n]==m, AppendTo[s,n]], {m, 1, 120000}]; s

%Y Cf. A001615, A002046, A033845 (Dedekind psi perfect numbers), A323327, A323328, A323329.

%K nonn

%O 1,1

%A _Amiram Eldar_, Jan 11 2019

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Last modified July 22 21:11 EDT 2024. Contains 374544 sequences. (Running on oeis4.)