A110797 a(0) = 1, a(1) = 2; then all the products generated by these numbers, then the next number 3 and so on.

1, 2, 3, 6, 4, 8, 12, 24, 5, 10, 15, 20, 30, 40, 60, 120, 6, 12, 18, 24, 30, 36, 48, 60, 72, 90, 120, 144, 180, 240, 360, 720, 7, 14, 21, 28, 35, 42, 42, 56, 70, 84, 84, 105, 126, 140, 168, 168, 210, 210, 252, 280, 336, 420, 420, 504, 630, 840, 840, 1008, 1260, 1680

Offset: 0

Author

Amarnath Murthy, Aug 13 2005

Keywords

• nonn

Comments

a(2^n) = n+2.

Differs from A083872 starting at a(16)=6.

"All the products generated by these numbers" means "the product of the most recently added singleton with each of the previous terms, sorted by size." - Joel B. Lewis, Nov 15 2006

Links

• Ivan Neretin, Table of n, a(n) for n = 0..1023

Programs

Mathematica

a = {1, 2}; Do[a = Join[a, Sort[n*a]], {n, 3, 7}]; a (* Ivan Neretin, May 09 2015 *)

Extensions

Extended by Ray Chandler, Aug 23 2005