A246647 Starting numbers k = a(n) for the (modified) Collatz map iteration which survive in the sieved Collatz table of A246646.

2, 3, 6, 7, 9, 12, 15, 16, 18, 19, 21, 24, 25, 27, 28, 30, 33, 34, 36, 37, 39, 42, 43, 45, 48, 51, 52, 54, 55, 57, 60, 63, 64, 66, 69, 70, 72, 73, 75, 78, 79, 81, 82, 84, 87, 88, 90, 93, 96, 97, 99, 100, 102, 105, 106, 108, 109, 111, 114, 115

Offset: 1

Author

Wolfdieter Lang, Oct 02 2014

Keywords

• nonn
• easy

Comments

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.

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.

Crossrefs

Cf. A246646.