%I #9 Jan 20 2021 17:57:11
%S 3,7,19,29,43,103,103,191,137,317,311,439,379,463,967,607,709,1061,
%T 1013,829,1021,1319,1201,1493,1499,2143,1973,2459,2333,2203,3697,3089,
%U 3923,2909,3449,4517,3539,4451,3923,4801,4007,4799,4793,3727,5651,4349,5591,4793,6581,8059,6043,9769,5507,6997
%N a(n) is the least prime p such that there is at least one prime <= p in each congruence class mod prime(n).
%C a(n) is the maximum of row n of A340753.
%H Robert Israel, <a href="/A340752/b340752.txt">Table of n, a(n) for n = 1..2000</a>
%e a(3) = 19 because with prime(3)=5, the first primes in each congruence class are 5 == 0 (mod 5), 11 == 1 (mod 5), 2 == 2 (mod 5), 3 == 3 (mod 5), and 19 == 4 (mod 5), and the maximum of these is 19.
%p g:= proc(p) local S,q;
%p S:= {$0..p-1};
%p q:= 1;
%p while S <> {} do
%p q:= nextprime(q);
%p S:= S minus {q mod p};
%p od;
%p q
%p end proc:
%p seq(g(ithprime(i)),i=1..100);
%Y Cf. A340753.
%K nonn
%O 1,1
%A _Robert Israel_, Jan 19 2021