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%I #6 Oct 02 2014 22:38:20
%S 2,3,6,7,9,12,15,16,18,19,21,24,25,27,28,30,33,34,36,37,39,42,43,45,
%T 48,51,52,54,55,57,60,63,64,66,69,70,72,73,75,78,79,81,82,84,87,88,90,
%U 93,96,97,99,100,102,105,106,108,109,111,114,115
%N Starting numbers k = a(n) for the (modified) Collatz map iteration which survive in the sieved Collatz table of A246646.
%C The (modified or Terras) Collatz map is T(k) = (3*k+1)/2 if k is odd and T(k) = k/2 if k is even, where k is a positive integer.
%C 1 is not listed because it appears in row n=1 for k=2 of A246646 . 4 does not appear because 4 = A246646(2,4). Similarly 5 = A246646(2,2), 8 = A246646(2,3), 10 = A246646(4,7), 11 = A246646(4,2), 13 = A246646(4,5), 14 = A246646(5,2), etc.
%Y Cf. A246646.
%K nonn,easy
%O 1,1
%A _Wolfdieter Lang_, Oct 02 2014