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Numbers k such that A169611(k) = 1.
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%I #18 Jan 16 2022 08:19:13

%S 2,3,10,14,15,21,22,26,33,34,38,39,46,50,51,57,58,62,69,70,74,75,82,

%T 86,87,93,94,98,105,106,110,111,118,122,123,129,130,134,141,142,146,

%U 147,154,158,159,165,166,170,177,178,182,183,190,194,195,201,202,206,213

%N Numbers k such that A169611(k) = 1.

%C Appears to be numbers k such that tau(36*k) = 2*tau(6*k). - _Gary Detlefs_, Jan 13 2020

%C The asymptotic density of this sequence is 5/18. - _Amiram Eldar_, Jan 16 2022

%H Amiram Eldar, <a href="/A171126/b171126.txt">Table of n, a(n) for n = 1..10000</a>

%t f[n_] := Plus @@ Last /@ Select[ FactorInteger@ n, 1 < #[[1]] < 4 &]; Select[ Range@ 213, f@# == 1 &] (* _Robert G. Wilson v_, Dec 19 2009 *)

%o (PARI) isok(n) = valuation(n, 2)+valuation(n, 3) == 1; \\ _Michel Marcus_, Jan 13 2020

%Y Cf. A000005 (tau), A169611.

%K nonn,easy

%O 1,1

%A _Juri-Stepan Gerasimov_, Dec 04 2009

%E More terms from _Robert G. Wilson v_, Dec 19 2009