[seqfan] Re: A167827 Prime numbers such that the hexadecimal representation use only the digits A, B, C, D, E, F (and not the decimal digits).

Richard Mathar mathar at strw.leidenuniv.nl
Fri Nov 13 22:42:49 CET 2009


jvp> Seqfan Mailing list - http://list.seqfan.eu/
jvp> Date: Fri, 13 Nov 2009 12:28:08 -0800
jvp> From: Jonathan Post <jvospost3 at gmail.com>
jvp> Subject: [seqfan] A167827 Prime numbers such that the hexadecimal representation use only the digits A, B, C, D, E, F (and not the decimal digits).
jvp> ...
jvp> 
jvp> I was expecting something that I could intersect with
jvp> 
jvp> A132675 	Decimal number representations of hexadecimal numbers whose
jvp> form spells an American-English word found in a standard dictionary in
jvp> lexicographic order.
jvp> 
jvp> In that latter seq, the first primes (as read in base 10) seems to be:
jvp> A132675 (8) = 44269
jvp> A132675 (9) = 173
jvp> no more through
jvp> A132675 (33) .

I get only 5 primes out of the total word list (up to "feed") of the Mma code:
44269
173
3499
233811181
4013

The Maple program (to blame is something is wrong)

L := [
a, aba, abaca, abed, accede, acceded, ace, aced, ad, add, added, baa, baad, babe,
bad, bade, baff, baffed, be, bead, beaded, bed, bedded, bee, beef, beefed, cab,
cad, cade, cafe, cede, ceded, cee, dab, dabbed, dace, dad, daff, dead, deaf,
decade, dee, deed, deeded, deface, defaced, ebb, ebbed, efface, effaced, fa,
facade, face, faced, fad, fade, faded, fed, fee, feed
] ;
for w in L do
        cars := convert(w,decimal,16) ;
        if isprime(cars) then
                print(cars) ;
        end if;
end do:




More information about the SeqFan mailing list