

A155961


Numbers whose square can be expressed as the sum of two positive cubes in at least 3 ways.


4




OFFSET

1,1


COMMENTS

Although this sequence has keyword "bref", this sequence is infinite since if n is in this sequence, then n*k^3 is in this sequence for all k > 0.  Altug Alkan, May 10 2016


LINKS

Table of n, a(n) for n=1..3.
Uwe Hollerbach, Taxi, Taxi! [Original link, broken]
Uwe Hollerbach, Taxi, Taxi! [Replacement link to Wayback Machine]
Uwe Hollerbach, Taxi! Taxi! [Cached copy from Wayback Machine, html version of top page only]


FORMULA

a(n) = sqrt(A155960(n)).


EXAMPLE

a(1)=3343221000 where 3343221000^2 = 279300^3 + 2234400^3 = 790020^3 + 2202480^3 = 1256850^3 + 2094750^3.


CROSSREFS

Cf. A051302, A155960.
Sequence in context: A340133 A309003 A251523 * A282401 A063412 A184672
Adjacent sequences: A155958 A155959 A155960 * A155962 A155963 A155964


KEYWORD

nonn,hard,more,bref


AUTHOR

Ray Chandler, Jan 31 2009


STATUS

approved



