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A155961 Numbers whose square can be expressed as the sum of two positive cubes in at least 3 ways. 4
3343221000, 26745768000, 90266967000 (list; graph; refs; listen; history; text; internal format)
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

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Last modified September 22 02:38 EDT 2021. Contains 347605 sequences. (Running on oeis4.)