Open main menu
Home
Random
Recent changes
Special pages
Community portal
Preferences
About Wikipedia
Disclaimers
Incubator escapee wiki
Search
User menu
Talk
Dark mode
Contributions
Create account
Log in
Editing
Centered cube number
(section)
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
==Properties== Because of the factorization {{math|(2''n'' + 1)(''n''<sup>2</sup> + ''n'' + 1)}}, it is impossible for a centered cube number to be a [[prime number]].<ref>{{Cite OEIS|A005898}}</ref> The only centered cube numbers which are also the [[square number]]s are 1 and 9,<ref>{{citation | last = Stroeker | first = R. J. | title = On the sum of consecutive cubes being a perfect square | journal = [[Compositio Mathematica]] | volume = 97 | year = 1995 | issue = 1β2 | pages = 295β307 | mr = 1355130 | url = http://www.numdam.org/item?id=CM_1995__97_1-2_295_0}}.</ref><ref>{{citation|title=The Magic Numbers of the Professor|series=MAA Spectrum|first1=Owen|last1=O'Shea|first2=Underwood|last2=Dudley|publisher=Mathematical Association of America|year=2007|isbn=9780883855577|page=17|url=https://books.google.com/books?id=RC9304k036YC&pg=PA17}}.</ref> which can be shown by solving {{math|''x''<sup>2</sup> {{=}} ''y''<sup>3</sup> + 3''y'' }}, the only integer solutions being (x,y) from {(0,0), (1,2), (3,6), (12,42)}, By substituting a=(x-1)/2 and b=y/2, we obtain x^2=2y^3+3y^2+3y+1. This gives only (a,b) from {(-1/2,0), (0,1), (1,3), (11/2,21)} where a,b are half-integers.
Edit summary
(Briefly describe your changes)
By publishing changes, you agree to the
Terms of Use
, and you irrevocably agree to release your contribution under the
CC BY-SA 4.0 License
and the
GFDL
. You agree that a hyperlink or URL is sufficient attribution under the Creative Commons license.
Cancel
Editing help
(opens in new window)