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 A294576 Odd numbers n such that 2 * A243823(n) > n. 2

%I

%S 945,1155,1365,1575,1785,1995,2145,2205,2415,2625,2805,2835,3003,3045,

%T 3135,3255,3315,3465,3675,3705,3795,3885,4095,4125,4305,4455,4485,

%U 4515,4725,4785,4845,4935,5115,5145,5355,5445,5565,5655,5775,5865,5985

%N Odd numbers n such that 2 * A243823(n) > n.

%C Odd terms in A294575.

%C 2^k - 1 is in the sequence for k = 12, 20, 24, 28, 30, 36, 40, 48, ...

%H Michael De Vlieger, <a href="/A294576/b294576.txt">Table of n, a(n) for n = 1..10000</a>

%t Select[Range[1, 6000, 2], Function[n, 2 (n - (Count[Range@ n, _?(PowerMod[n, Floor@ Log2@ n, #] == 0 &)] + EulerPhi[n] - 1)) > n]]

%Y Cf. A243823, A272619, A294575.

%K nonn

%O 1,1

%A _Michael De Vlieger_, Nov 17 2017

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Last modified December 4 09:10 EST 2021. Contains 349484 sequences. (Running on oeis4.)