|
| |
|
|
A145553
|
|
Numbers n such that n^2 can be expressed as the sum of 2 positive cubes in exactly 2 different ways.
|
|
3
| |
|
|
77976, 223587, 623808, 894348, 1788696, 2105352, 2989441, 4298427, 4672423, 4990464, 5986575, 6036849, 7154784, 8437832, 9747000, 14309568, 16842816, 23915528, 24147396, 24770529, 26745768, 27948375, 34387416, 34634719, 36570744, 37379384, 39923712, 47892600
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
COMMENTS
| This is conjectured to be an infinite sequence
Subsequence of A051302. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 14 2008]
First differs from A051302 at A051302(172)=3343221000 where 3343221000^2 = 279300^3 + 2234400^3 = 790020^3 + 2202480^3 = 1256850^3 + 2094750^3.
|
|
|
LINKS
| Ray Chandler, Table of n, a(n) for n = 1..771
|
|
|
EXAMPLE
| a(1): 77976^2 = 6080256576 = 1824^3 + 228^3 = 1710^3 + 1026^3; a(2): 223587^2 = 49991146569 = 3666^3 + 897^3 = 3276^3 + 2457^3; a(3): 623808^2 = 389136420864 = 7296^3 + 912^3 = 6840^3 + 4104^3; a(4): 894348^2 = 799858345104 = 9282^3 + 546^3 = 9009^3 + 4095^3
|
|
|
CROSSREFS
| Cf. A145552, A051302.
Sequence in context: A133974 A061528 A051302 * A016819 A016855 A016975
Adjacent sequences: A145550 A145551 A145552 * A145554 A145555 A145556
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Iain Renfrew (iain.renfrew(AT)btinternet.com), Oct 13 2008
|
|
|
EXTENSIONS
| a(5)-a(15) from Zak Seidov (zakseidov(AT)yahoo.com), Oct 15 2008
Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Nov 22 2011
|
| |
|
|
