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A203444 Numbers in range of Dedekind Psi function: A001615. 4

%I #23 Dec 14 2018 12:25:03

%S 1,3,4,6,8,12,14,18,20,24,30,32,36,38,42,44,48,54,56,60,62,68,72,74,

%T 80,84,90,96,98,102,104,108,110,112,114,120,126,128,132,138,140,144,

%U 150,152,158,160,162,164,168,174,176,180,182,186,192,194,198,200

%N Numbers in range of Dedekind Psi function: A001615.

%C a(n) is even for n>2

%H Enrique Pérez Herrero, <a href="/A203444/b203444.txt">Table of n, a(n) for n = 1..5000</a>

%H Patrick Sole and Michel Planat, <a href="http://arxiv.org/abs/1011.1825">Extreme values of the Dedekind Psi function</a>, J. Comb. Number Theory 3 (2011), no. 1, 33-38, arXiv:1011.1825v2.

%t terms = 100; Clear[seq]; seq[k_] := seq[k] = Table[DirichletConvolve[j, MoebiusMu[j]^2, j, n], {n, 1, k terms}] // Union // PadRight[#, terms]&;

%t seq[k = 1]; seq[k++]; While[Print[k]; seq[k] != seq[k-1], k++];

%t seq[k] (* _Jean-François Alcover_, Dec 14 2018, after _Jan Mangaldan_ in A001615 *)

%Y Cf. A001615, A175836, A060648.

%Y Cf. A007617.

%Y Cf. A002202.

%K nonn

%O 1,2

%A _Enrique Pérez Herrero_, Jan 02 2012

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