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-   -   What's the next term in the sequence (part deux)? (https://www.mersenneforum.org/showthread.php?t=6924)

grandpascorpion 2007-01-11 01:49

What's the next term in the sequence (part deux)?
 
5,22,102,510,82110,17490,?

The solution involves basic number theory.

39 and values derived from fitted polynomials aren't what I'm looking for :)

grandpascorpion 2007-01-11 03:39

Ugh, one of the terms was wrong. Here's the correct sequence:
 
5,22,102,510,3210,17490,?

xilman 2007-01-11 08:36

[QUOTE=grandpascorpion;95781]5,22,102,510,82110,17490,?

The solution involves basic number theory.

39 and values derived from fitted polynomials aren't what I'm looking for :)[/QUOTE]

42 ;-)

Paul

akruppa 2007-01-11 09:52

%I A048251
%S A048251 5,22,102,510,3210,17490,112890,600270
%N A048251 Smallest number whose sum of divisors is 6^n.
%F A048251 a(n)=Min{x : A000203(x)=6^n}
%e A048251 Sigma[x]=1296=6.6.6.6 if x={510, 642, 710, 742, 782, 795, 862, 935, 1177, 1207, 1219}; the smallest is a(4)=510.
%Y A048251 A006532, A020477, A019422, A019423, A018427.
%Y A048251 Sequence in context: A083586 A087439 A033452 this_sequence A017971 A017972 A008485
%Y A048251 Adjacent sequences: A048248 A048249 A048250 this_sequence A048252 A048253 A048254
%K A048251 nonn
%O A048251 1,1
%A A048251 Labos E. (labos(AT)ana.sote.hu)

Alex

grandpascorpion 2007-01-11 13:19

Yep, I came up with this and found the sequence later (once the minimum terms were correct).

I was thinking that the sigma would be the perfect power of a number n such that n had two or more factors. In this context, that would seem to mean n=2*3. That would be an interesting thing to prove I think.


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