|
| |
|
|
A087887
|
|
a(n) = 18n^3 + 6n^2.
|
|
1
| |
|
|
0, 24, 168, 540, 1248, 2400, 4104, 6468, 9600, 13608, 18600, 24684, 31968, 40560, 50568, 62100, 75264, 90168, 106920, 125628, 146400, 169344, 194568, 222180, 252288, 285000, 320424, 358668, 399840, 444048, 491400, 542004, 595968, 653400
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
COMMENTS
| Another parametric representation of the solutions of the Diophantine equation x^2 - y^2 =z^3 is (x,y,z) = (15n^3, 3n^3, 6n^2), thus getting a(n) = 18n^3 + 6n^2.
|
|
|
FORMULA
| O.g.f.: 12x(2+6x+x^2)/(-1+x)^4. a(n)=12*A036659(n). - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 07 2008
|
|
|
CROSSREFS
| Cf. A085409, A085482.
Sequence in context: A186862 A136380 A019583 * A166756 A165187 A052761
Adjacent sequences: A087884 A087885 A087886 * A087888 A087889 A087890
|
|
|
KEYWORD
| easy,nonn
|
|
|
AUTHOR
| Jun Mizuki (suzuki32(AT)sanken.osaka-u.ac.jp), Oct 13 2003
|
|
|
EXTENSIONS
| More terms from Ray Chandler (rayjchandler(AT)sbcglobal.net), Nov 06 2003
|
| |
|
|
