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%I #10 Jul 29 2023 14:47:00
%S 5,7,41,479,59,266681,63397,514639,178939,242101,18500393,40799043101,
%T 190297,1844659,78206663,616798327,38512247,86364397717734821,
%U 421950627598601,84786899,52030193,31411862913089,1422157053067,47961582392203,8408339,6269019298981
%N Largest prime factor of the n-th central factorial number A001819(n).
%H Daniel Suteu, <a href="/A120298/b120298.txt">Table of n, a(n) for n = 2..180</a>
%F a(n) = A006530(A001819(n)). - _Daniel Suteu_, Jun 10 2022
%t Table[Max[FactorInteger[Sum[1/i^2,{i,1,n}]/Product[1/i^2,{i,1,n}]]],{n,2,30}]
%t Table[FactorInteger[n!^2*HarmonicNumber[n,2]][[-1,1]],{n,2,30}] (* _Harvey P. Dale_, Jul 29 2023 *)
%o (PARI) a(n) = vecmax(factor(n!^2 * sum(k=1, n, 1/k^2))[,1]); \\ _Daniel Suteu_, Jun 10 2022
%Y Cf. A001819, A002701, A007406.
%K nonn
%O 2,1
%A _Alexander Adamchuk_, Jul 11 2006
%E More terms from _Daniel Suteu_, Jun 10 2022
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