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%I #25 May 28 2022 07:00:19
%S 3,13,71,4733,1806113,1803647,2699538733,109912203092239643840221,
%T 1920647391913,549334763,
%U 568972471024107865287021434301977158534824481,41903425553544839998158239,5926187589691497537793497756719,19825223972382274003506149120708429799166030881820329892377241,194707033016099228267068299180244011637
%N Largest prime factor of (p^p-1)/(p-1) where p = prime(n).
%H Daniel Suteu, <a href="/A214812/b214812.txt">Table of n, a(n) for n = 1..33</a>
%H T. S. Motzkin, <a href="/A000262/a000262.pdf">Sorting numbers for cylinders and other classification numbers</a>, in Combinatorics, Proc. Symp. Pure Math. 19, AMS, 1971, pp. 167-176. [Annotated, scanned copy]
%F a(n) = A006530(A001039(n)). - _Daniel Suteu_, May 26 2022
%t FactorInteger[#][[-1,1]]&/@Table[(p^p-1)/(p-1),{p,Prime[Range[15]]}] (* _Harvey P. Dale_, Aug 27 2016 *)
%o (PARI) a(n) = my(p=prime(n)); vecmax(factor((p^p-1)/(p-1))[,1]); \\ _Daniel Suteu_, May 26 2022
%Y Cf. A001039, A088807, A125135, A212552, A214811.
%K nonn
%O 1,1
%A _N. J. A. Sloane_, Jul 31 2012
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