%I #22 Jun 28 2023 12:37:08

%S 0,1,3,7,9,11,31,39,47,211,217,223,229,235,243,249,255,261,267,275,

%T 281,287,293,299,2311,2347,2383,2419,2455,2523,2559,2595,2631,2667,

%U 2735,2771,2807,2843,2879,30031,30061,30091,30121,30151,30181,30211,30247,30277,30307

%N Numbers that are palindromes in primorial base.

%H Amiram Eldar, <a href="/A333423/b333423.txt">Table of n, a(n) for n = 1..2500</a>

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Mixed_radix#Primorial_number_system">Primorial number system</a>.

%H <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>.

%e 3 is a term since its representation in primorial base is 11 (1 * 2# + 1) which is a palindrome.

%e 7 is a term since its representation in primorial base is 101 (1 * 3# + 0 * 2# + 1 = 6 + 1) which is a palindrome.

%t max = 6; bases = Prime @ Range[max, 1, -1]; nmax = Times @@ bases - 1; Select[Range[0, nmax], PalindromeQ @ IntegerDigits[#, MixedRadix[bases]] &]

%Y Cf. A049345, A235168.

%Y Cf. A002113, A006995, A014190, A014192, A029952, A029953, A029954, A029803, A029955, A046807.

%K nonn,base

%O 1,3

%A _Amiram Eldar_, Mar 20 2020