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 A124875 #21 May 16 2023 17:29:21
%S A124875 3,251,37,5449,53,2591,2538983,462191,4957,5042929,151099201553,
%T A124875 119465070161,8868751511,56154295334575853,4480577578703,
%U A124875 1254664312327399,34237559,1683118856778495358491487,294307265949353,46956374669685791,46572151,110732345922475922393023393
%N A124875 Greatest prime dividing A007408(n).
%C A124875 For all n>2, the exponent of a(n) in the factorization of A007408(n) appears to be 1.
%H A124875 Sean A. Irvine, <a href="/A124875/b124875.txt">Table of n, a(n) for n = 2..131</a> (a(50) corrected, Mar 14 2023, terms 2..106 from Amiram Eldar)
%F A124875 a(n) = A006530(A007408(n)). - _Amiram Eldar_, Feb 09 2020
%e A124875 The offset is 2 since A007408(1) = 1 has no prime divisors at all.
%e A124875 a(2) = 3 is the largest prime dividing A007408(2) = 9,
%e A124875 a(3) = 251 is the largest prime dividing A007408(3) = 251,
%e A124875 a(4) = 37 since A007408(4) = 5 * 11 * 37.
%p A124875 seq(op([ -1,-2],op(-1,ifactors(A007408(n)))),n=2..25);
%t A124875 Table[FactorInteger[Numerator[Sum[1/k^3, {k, 1, n}]]][[-1, 1]], {n, 2, 20}] (* _Amiram Eldar_, Feb 09 2020 *)
%Y A124875 Cf. A007408, A124876, A124877.
%K A124875 nonn
%O A124875 2,1
%A A124875 _M. F. Hasler_, Nov 11 2006
%E A124875 Data corrected and extended by _Amiram Eldar_, Feb 09 2020