|
|
|
|
|
|
|
|
|
#19 by N. J. A. Sloane at Sun Aug 11 14:41:30 EDT 2024
|
|
| LINKS
|
P. De Geest, <a href="httphttps://www.worldofnumbers.com/palpri.htm">World!Of Palindromic Primes</a>
|
|
|
|
|
Discussion
|
| Sun Aug 11
| 14:41
| OEIS Server: https://oeis.org/edit/global/2998
|
|
|
|
|
|
|
#18 by R. J. Mathar at Sat Oct 17 18:09:23 EDT 2015
|
|
|
|
|
|
|
|
#17 by R. J. Mathar at Sat Oct 17 18:08:52 EDT 2015
|
|
|
|
|
|
|
|
#16 by Giovanni Resta at Wed Aug 19 06:02:21 EDT 2015
|
|
|
|
|
|
|
|
#15 by Michel Marcus at Wed Aug 19 05:09:35 EDT 2015
|
|
|
|
|
|
|
|
#14 by Robert Israel at Wed Aug 19 02:51:54 EDT 2015
|
|
|
|
|
|
|
|
#13 by Robert Israel at Wed Aug 19 02:50:54 EDT 2015
|
|
| MAPLE
|
N:= 14: # to get all terms < 3^N
Res:= 2:
digrev:=proc(n) local L;
L:= convert(n, base, 3);
add(L[-i]*3^(i-1), i=1..nops(L))
end proc;
for d from 2 to N do
if d::even then
m:= d/2;
Res:= Res, op(select(isprime, [seq](n*3^m + digrev(n), n=3^(m-1)..3^m-1)));
else
m:= (d-1)/2;
Res:= Res, op(select(isprime, [seq](seq(n*3^(m+1)+y*3^m+digrev(n),
y=0..2), n=3^(m-1)..3^m-1)));
fi
od:
Res; # Robert Israel, Aug 19 2015
|
|
| STATUS
|
reviewed
editing
|
|
|
|
|
|
|
#12 by Joerg Arndt at Wed Aug 19 02:23:40 EDT 2015
|
|
|
|
|
|
|
|
#11 by Michel Marcus at Wed Aug 19 02:00:12 EDT 2015
|
|
|
|
|
|
|
|
#10 by Michel Marcus at Wed Aug 19 01:59:56 EDT 2015
|
|
|
|
|
|
|
