COMMENT on A114717. Increasing compositeness?
Mitch Harris
Harris.Mitchell at mgh.harvard.edu
Fri Jan 13 16:01:00 CET 2006
Antti Karttunen wrote:
>
> Now it would be also interesting to compute the positions (and values)
> where this sequence A114717
> obtains A) distinct new values (i.e. 1,2,5,14,48,42,2452,462, etc. and
> the positions where they occur, i.e. 1,6,12,24,30,36,...)
> and B) records (i.e. 1,2,5,14,48,2452, and their positions:
> 1,6,12,24,30,60, ....)
> and does any of these four sequences occur already in OEIS,
A quick search gets nothing. The "value" sequences will be just as hard
(if not harder) to compute as the original. As to the "records" sequences...
> and if not,
> then whether they give
> us a yet another useful measure of "increasing compositeness" ?
I would think that the factorization would be the best measure of
compositeness (or even just the exponents in the factorization, which is
all that the # of linear extensions of the divisor lattice depends on).
Like the example in the comments, a(12) = a(75) because both have the
factorization exponent signature of (2, 1), so I would say that 12 and
75 are equally 'composite'.
The set of numbers that are the least in their equivalence class of
exponent signatures is a related idea. So 12 would be in the set, but
not 18, 20, 45, 75, etc.
See A025487: Least integer of each prime signature
Mitch
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