[seqfan] Re: 2^n - 2

[Ray Chandler]

> I just submitted this sequence. Can someone answer the 
> question in the comment line?
> 
> %I A159353
> %S A159353 1,1,1,2,1,3,1,4,3,5,1,6,1,7,5,8,1,9,1,10
> %N A159353 a(n) = the smallest positive integer such that 
> a(n) *(2^n -2) is a multiple of n. 
> %C A159353 This is not the same sequence as sequence A032742, 
> where A032742(n) = the largest proper divisor of n. For which 
> n do the sequences A032742 and A159353 differ? 
> %Y A159353 A000918
> %K A159353 more,nonn
> %O A159353 1,4
> 
> Thanks,
> Leroy Quet
> 

Sequences differ where GCD[n, 2^n-2] does not equal least prime factor of n:

28, 35, 45, 55, 70, 77, 95, 105, 112, 115, 119, 143, 153, 154, 155, 161, 165, 175, 186, 187, 196, ...
Ray