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 A358275 #49 Apr 16 2023 13:40:56
%S A358275 2,71,2,5,2,1141871,2,3,2,58728589,2,3,2,5,2,3,2,277,2,4643,2,29,2,5,
%T A358275 2,3,2,37,2,3,2,13,2,3,2,264439098646852541,2,7,2,53,2,7,2,3,2,587,2,
%U A358275 3,2,45307,2,3,2,5,2,11,2,7,2,13,2,3,2,5,2,3,2,17,2,3,2,983,2,5,2,53,2,11
%N A358275 Least prime factor of A098129(n).
%F A358275 a(n) = A020639(A098129(n)).
%F A358275 a(n) = 2 if n is even. - _Chai Wah Wu_, Apr 15 2023
%e A358275 a(3) = 71 because 71 is the smallest prime factor of A098129(3) = 122333.
%e A358275 a(7) = 1141871 because 1141871 is the smallest prime factor of A098129(7) = 1223334444555556666667777777.
%o A358275 (Python)
%o A358275 from sympy import primefactors
%o A358275 def A358275(n): return min(primefactors(int(''.join(str(j)*j for j in range(1,n+1))))) if n&1 else 2 # _Chai Wah Wu_, Apr 15 2023
%Y A358275 Cf. A020639, A098129.
%K A358275 nonn
%O A358275 2,1
%A A358275 _David Cleaver_, Mar 26 2023