%I #5 May 23 2021 02:50:59
%S 2,3,5,7,4,6,3,2,6,3,7,4,4,3,4,5,2,7,10,3,3,2,6,2,3,6,2,3,2,4,4,4,2,2,
%T 2,4,2,4,4,4,2,4,2,10,3,3,2,3,4,3,9,2,2,3,3,4,3,2,3,2,3,2,3,2,3,2,4,3,
%U 2,4,6,4,2,3,2,3,2,2,2,5,2,4,4,3,2,3,6,2,3,4,2,3,3,6,2,4,3,4,2,2,2,2,2
%N Least base for which the n-th prime has no prime reversal in that base.
%C a(n) is always less than or equal to n-th prime and once past a(6) it is always less than n.
%H Amiram Eldar, <a href="/A075241/b075241.txt">Table of n, a(n) for n = 1..10000</a>
%t a = {}; Do[k = 2; p = Prime[n]; While[ PrimeQ[ FromDigits[ Reverse[ IntegerDigits[p, k]], k]], k++ ]; a = Append[a, k], {n, 1, 105}]; a
%Y Cf. A075240, A075242.
%K base,easy,nonn
%O 1,1
%A _Robert G. Wilson v_, Sep 09 2002