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A281794 The largest prime factor of (1+n^2)*(1+n^3).

%I A281794 #14 Sep 08 2022 08:46:18
%S A281794 1,2,5,7,17,13,37,43,19,73,101,61,29,157,197,211,257,29,307,181,401,
%T A281794 421,463,53,577,601,677,73,757,421,67,37,331,151,1123,613,1297,137,67,
%U A281794 1483,1601,547,1723,139,631,1013,109,103,461,1201,61,2551,541,919
%N A281794 The largest prime factor of (1+n^2)*(1+n^3).
%H A281794 Vincenzo Librandi, <a href="/A281794/b281794.txt">Table of n, a(n) for n = 0..1000</a>
%F A281794 a(n) = max( A014442(n), A081256(n)).
%F A281794 a(n) = A006530(A281661(n)).
%p A281794 A281794 := proc(n)
%p A281794     A006530((1+n^2)*(1+n^3)) ;
%p A281794 end proc:
%p A281794 seq(A281794(n),n=0..60) ;
%t A281794 Table[Max[Transpose[FactorInteger[(1 + n^2) (1 + n^3)]][[1]]], {n, 0, 60}] (* _Vincenzo Librandi_, Jun 03 2017 *)
%o A281794 (Magma) [#f eq 0 select 1 else f[ #f][1] where f is Factorization((1+n^2)*(1+n^3)): n in [0..60]]; // _Vincenzo Librandi_, Jun 03 2017
%o A281794 (PARI) a(n) = if (n==0, 1, my(f=factor((1+n^2)*(1+n^3))); vecmax(f[, 1])); \\ _Michel Marcus_, Jun 03 2017; corrected Jun 13 2022
%Y A281794 Cf. A006530, A014442, A081256, A281661.
%K A281794 nonn,easy
%O A281794 0,2
%A A281794 _R. J. Mathar_, Jan 30 2017