A178170 The product of the numbers in the Collatz trajectory of a(n) is the n-th largest such product.

1, 2, 4, 8, 16, 5, 32, 10, 3, 6, 20, 64, 12, 40, 21, 24, 128, 13, 42, 80, 48, 26, 256, 84, 160, 52, 96, 85, 17, 168, 53, 512, 104, 320, 192, 34, 170, 106, 11, 336, 208, 68, 1024, 384, 22, 35, 640, 340, 212, 7, 69, 136, 44, 672, 416, 70, 14, 341, 213, 113, 768, 2048, 1280

Offset: 1

Author

T. D. Noe, May 21 2010

Keywords

• nonn

Comments

That is, a(n) is the number k such that A178168(k) = A178169(n).

The sequence is easy to compute by generating the Collatz tree while keeping track of the products at the leaves of the tree. At each step, extend the tree at the leaf having the smallest product.

Links

• T. D. Noe, Table of n, a(n) for n=1..1000