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%I #30 Mar 13 2023 02:54:56
%S 2,3,2,7,2,5,3,5,7,5,7,5,127,7,8191,5,127,13,31,127,127,89,31,17,127,
%T 31,3221,179,151,127,8191,13,262657,11939,199,257,127,127,337,257,
%U 524287,73,1093,547,137,241,1093,547,331,131071,1093,599479,8191,137,127,8191
%N Greatest prime factor of A007497(n).
%H Amiram Eldar, <a href="/A333986/b333986.txt">Table of n, a(n) for n = 1..1000</a>
%F a(n) = A006530(A007497(n)). - _Michel Marcus_, Sep 09 2020
%t f[1] = 2; f[n_] := f[n] = DivisorSigma[1, f[n - 1]]; Table[FactorInteger[f[n]][[-1, 1]], {n, 50}] (* _Amiram Eldar_, Sep 23 2020 *)
%Y Cf. A006530, A007497.
%K nonn
%O 1,1
%A _Richard Peterson_, Sep 04 2020
%E More terms from _Michel Marcus_, Sep 16 2020