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

%I #9 May 09 2015 13:39:53

%S 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,

%T 90,120,144,180,240,360,720,7,14,21,28,35,42,42,56,70,84,84,105,126,

%U 140,168,168,210,210,252,280,336,420,420,504,630,840,840,1008,1260,1680

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

%C a(2^n) = n+2.

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

%C "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

%H Ivan Neretin, <a href="/A110797/b110797.txt">Table of n, a(n) for n = 0..1023</a>

%t a = {1, 2}; Do[a = Join[a, Sort[n*a]], {n, 3, 7}]; a (* _Ivan Neretin_, May 09 2015 *)

%K nonn

%O 0,2

%A _Amarnath Murthy_, Aug 13 2005

%E Extended by _Ray Chandler_, Aug 23 2005