A187108 - OEIS

%I #21 Sep 30 2025 17:26:11

%S 1,3,7,9,15,19,21,25,27,33,37,39,43,45,51,55,57,63,69,73,75,79,81,87,

%T 93,97,99,105,109,111,115,117,123,127,129,133,135,141,145,147,151,153,

%U 159,163,165,169,171,177,181,183,187,189,195,199,201,207,213,217

%N Odd numbers not in the trajectory of a smaller number under the Collatz (3x+1) iteration.

%C These are the odd numbers in A061641, which gives a more detailed explanation. - _T. D. Noe_, Mar 05 2011

%Y Cf. A061641.

%K nonn

%O 1,2

%A _Jimin Park_, Mar 05 2011