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A181659 Numbers at which the sum of the iterated totient function (A092693) attains a record. 2

%I

%S 1,2,3,5,7,11,13,17,23,29,37,41,47,53,59,71,73,79,83,89,101,107,131,

%T 137,167,179,227,233,257,289,317,347,359,389,443,449,461,467,503,557,

%U 563,569,587,641,719,809,839,857,929,977,983,1013,1019,1097,1187,1193,1283

%N Numbers at which the sum of the iterated totient function (A092693) attains a record.

%C Most of these numbers are prime. The first four composites are 289, 2329, 4369, and 4913.

%H T. D. Noe, <a href="/A181659/b181659.txt">Table of n, a(n) for n=1..1000</a>

%t kMax=2*3*5*7*11*13; t=Table[0,{kMax}]; Do[e=EulerPhi[k]; t[[k]]=e+t[[e]], {k,2,kMax}]; mx=-1; Reap[Do[If[t[[k]]>mx, mx=t[[k]]; Sow[k]], {k,kMax}]][[2,1]]

%Y Cf. A181660

%Y Cf. A126106 (record values)

%K nonn

%O 1,2

%A _T. D. Noe_, Nov 04 2010

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Last modified May 19 20:41 EDT 2019. Contains 323410 sequences. (Running on oeis4.)