This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A075306 #6 Mar 11 2023 15:20:22
%S A075306 3,25,91,2101,23101,60061,510511,29099071,3792578791,84106011991,
%T A075306 2005604901301,252305096583541,11561510014033981,52331045326680121,
%U A075306 31359378912013061911,1792403716245452460151,98060777857864844592571
%N A075306 Smallest number == 0 mod (n+1)-th prime and == 1 mod all smaller primes.
%H A075306 Harvey P. Dale, <a href="/A075306/b075306.txt">Table of n, a(n) for n = 1..349</a>
%e A075306 a(4) = 2101 == 0 mod 11 and 2101 == 1 mod (2*3*5*7)
%t A075306 Table[ChineseRemainder[PadLeft[{0},n,1],Prime[Range[n]]],{n,2,20}] (* _Harvey P. Dale_, Mar 11 2023 *)
%o A075306 (PARI) for(n=1,20,p=1:forprime(k=2, prime(n),p=p*k):pn=prime(n+1):s=0:while((s+1)%pn>0,s=s+p):print1(s+1","))
%K A075306 nonn
%O A075306 1,1
%A A075306 _Amarnath Murthy_, Sep 13 2002
%E A075306 More terms from _Ralf Stephan_, Mar 24 2003