[seqfan] A032734

Harvey P. Dale hpd1 at nyu.edu
Sat Oct 22 19:46:29 CEST 2011

	I am confused about this sequence.  It states that it comprises
numbers that "cannot be prefixed or followed by any digit to form a
prime."  One of its terms, e.g., is 25213, but 252139 is a prime.  Is
the definition wrong, or unclear, or is it simply that the term is
wrong?  If I treat the "or" in the definition as exclusive, so that
prepending digits is one test and appending digits is a separate test, I
generate lots of terms that aren't in the sequence.


-----Original Message-----
From: seqfan-bounces at list.seqfan.eu
[mailto:seqfan-bounces at list.seqfan.eu] On Behalf Of Maximilian Hasler
Sent: Saturday, October 22, 2011 1:09 PM
To: Sequence Fanatics Discussion list
Subject: [seqfan] Re: Strange comment in A003418

The contributor did not specify for which n this has to hold.

Obviously the inequality cannot hold for n=1, since the rhs is 0 and
the lhs nonnegative.


On Sat, Oct 22, 2011 at 6:31 AM, Georgi Guninski <guninski at guninski.com>
> A003418 a(0) = 1; for n >= 1, a(n) = least common multiple (or lcm) of
{1, 2, ..., n}
> An assertion equivalent to the Riemann hypothesis is: | log(a(n)) - n
| < sqrt(n) * log(n)^2. - Lekraj Beedassy (blekraj(AT)yahoo.com), Aug 27
> According to my computations the inequality fails for n in {1,2}.
> _______________________________________________
> Seqfan Mailing list - http://list.seqfan.eu/


Seqfan Mailing list - http://list.seqfan.eu/

More information about the SeqFan mailing list