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A210523
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Record values of Dedekind psi function.
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2
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1, 3, 4, 6, 12, 18, 24, 36, 48, 72, 96, 108, 144, 168, 192, 216, 240, 288, 360, 384, 432, 576, 648, 672, 720, 864, 1008, 1152, 1296, 1344, 1440, 1728, 1800, 2016, 2304, 2592, 2880, 3024, 3456, 4032, 4320, 4608, 5184
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OFFSET
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1,2
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COMMENTS
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Record values of A001615.
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LINKS
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Amiram Eldar, Table of n, a(n) for n = 1..808 (terms 1..373 from Enrique Pérez Herrero)
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FORMULA
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a(n) = A001615(A330006(n)). - Amiram Eldar, Nov 26 2019
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MAPLE
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N:= 100: # to get a(1) to a(N)
A001615 := proc(n) n*mul((1+1/i[1]), i=ifactors(n)[2]) end:
count:= 0:
val:= -infinity:
for i from 1 while count < N do
v:= A001615(i);
if v > val then
val:= v;
count:= count+1;
A[count]:=v;
fi
od:
seq(A[i], i=1..N); # Robert Israel, Nov 19 2014
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MATHEMATICA
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JordanTotient[n_, k_:1] := DivisorSum[n, #^k*MoebiusMu[n/#]&] /; (n>0) && IntegerQ[n]; DedekindPsi[n_] := JordanTotient[n, 2]/EulerPhi[n]; a=1; lst={a}; Do[b=DedekindPsi[n]; If[b>a, a=b; AppendTo[lst, b]], {n, 2000}]; lst
psi[1] = 1; psi[n_] := n * Times @@ (1 + 1/FactorInteger[n][[;; , 1]]); seq = {}; pmax = 0; Do[pmax = psi[n]; If[p > pmax, pmax = p; AppendTo[seq, p]], {n, 1, 10^5}]; seq (* Amiram Eldar, Nov 26 2019 *)
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CROSSREFS
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Cf. A002183, A006093, A330006 (the corresponding positions of records).
Sequence in context: A293593 A024373 A111159 * A109069 A329953 A329671
Adjacent sequences: A210520 A210521 A210522 * A210524 A210525 A210526
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KEYWORD
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nonn,changed
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AUTHOR
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Enrique Pérez Herrero, Jan 27 2013
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STATUS
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approved
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