[seqfan] Re: Do emirpimes with leading zeroes count?

Jonathan Post jvospost3 at gmail.com
Wed Dec 22 20:30:44 CET 2010

I stopped with Cf. A114015 Quaternary emirpimes, in Jun 13 2006
because of the "less" keyword.


1102 inserted by R. J. Mathr, Dec 22 2010 -- note that he
typographically shrank his name.

I am grateful, of course, for the correction and Maple.

Dr. Del Arte is quite right to raise this question.

-- Jonathan Vos Post

On Wed, Dec 22, 2010 at 9:58 AM, Alonso Del Arte
<alonso.delarte at gmail.com> wrote:
> In editing A119684, R. J. Mathar raised a very interesting point which is
> moot in base 10 but very relevant in prime bases, like ternary:
> Are multiples of the base, those numbers that end with zeroes, eligible for
> consideration as emirpimes, since their trailing zeroes will become leading
> zeroes upon reversal? For example, in ternary, 1220 becomes 0221, which is
> the square of 12, a prime.
> The Mathematica program I added to the sequence includes the condition
> gcd(n, 3) = 1; a simple cut allows the computer to consider numbers that are
> multiples of the base (a necessary provision only in prime bases if the
> concept of emirpimes is meant to exclude multiples of the base).
> Al
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