

A272897


Largest prime factor of nth taxicab number A001235(n).


1



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

1,1


COMMENTS

There are two versions of "taxicab numbers" that are A001235 and A011541. This sequence focuses on the version A001235.
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".
Is a(n) >= 13 for all n? This is true for n <= 10000.  Robert Israel, May 09 2016


LINKS

Robert Israel, Table of n, a(n) for n = 1..10000


FORMULA

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


EXAMPLE

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


MATHEMATICA

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 *)


CROSSREFS

Cf. A001235, A006530.
Sequence in context: A010858 A291499 A168525 * A040343 A022353 A323177
Adjacent sequences: A272894 A272895 A272896 * A272898 A272899 A272900


KEYWORD

nonn


AUTHOR

Altug Alkan, May 09 2016


STATUS

approved



