%I #22 May 14 2016 16:03:14

%S 19,19,19,43,19,13,43,19,37,79,19,19,79,79,43,61,79,127,19,19,13,43,

%T 109,19,37,139,43,19,37,31,79,43,19,139,127,127,13,19,19,61,103,151,

%U 409,73,181,13,277,79,43,79,79,19,43,139,61,19,61,79,103,127,19,37,79,163,79,19,19

%N Largest prime factor of n-th taxi-cab number A001235(n).

%C There are two versions of "taxicab numbers" that are A001235 and A011541. This sequence focuses on the version A001235.

%C All terms of this sequence are members of this sequence infinitely many times. For example, in this sequence there are infinitely many times "277" and there are infinitely many times "17".

%C Is a(n) >= 13 for all n? This is true for n <= 10000. - _Robert Israel_, May 09 2016

%H Robert Israel, <a href="/A272897/b272897.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A006530(A001235(n)).

%e a(1) = A006530(A001235(1)) = A006530(1729) = 19.

%t FactorInteger[Select[Range[2*10^5], Length[PowersRepresentations[#, 2, 3]] > 1 &]][[All, -1, 1]] (* _Michael De Vlieger_, May 10 2016, after _Harvey P. Dale_ at A001235 *)

%Y Cf. A001235, A006530.

%K nonn

%O 1,1

%A _Altug Alkan_, May 09 2016