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%I #26 Feb 21 2023 04:25:54
%S 1,5,11,59,179,1259,229,7559,37799,415799,17569,71437,18979,62597,
%T 1135133999,1646947,445771,277021,5499724229999,2217247573,721381,
%U 46313123,29220034833989999,16347569521,5464930609,4939567,319699160368361,2605998587146349,178974179,15701603,116318025830291273,126202964557
%N Greatest prime factor of A104357(n) = A104350(n) - 1.
%H Tyler Busby, <a href="/A104359/b104359.txt">Table of n, a(n) for n = 2..159</a> (terms 2..74 from Amiram Eldar, terms 75..145 from Max Alekseyev)
%H Reinhard Zumkeller, <a href="/A104350/a104350.txt">Products of largest prime factors of numbers <= n</a>
%F a(n) = A006530(A104357(n)).
%t a[n_] := FactorInteger[-1 + Product[FactorInteger[k][[-1, 1]], {k, 1, n}]][[-1, 1]]; Array[a, 50, 2] (* _Amiram Eldar_, Feb 12 2020 *)
%o (PARI) gpf(n) = if (n==1, 1, vecmax(factor(n)[,1])); \\ A006530
%o a(n) = gpf(prod(i=2, n, gpf(i))-1); \\ _Michel Marcus_, Feb 21 2023
%Y Cf. A006530, A002582, A002584, A104350, A104357, A104358, A104360, A104361, A104362, A104363, A104364, A104367.
%K nonn
%O 2,2
%A _Reinhard Zumkeller_, Mar 06 2005
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