|
|
A005988
|
|
x^3 + n*y^3 = 1 is solvable.
(Formerly M1732)
|
|
3
|
|
|
2, 7, 9, 17, 19, 20, 26, 28, 37, 43, 63, 65, 91, 124, 126, 182, 215, 217, 254, 342, 344, 422, 511, 513, 614, 635, 651, 728, 730, 813, 999, 1001, 1330, 1332, 1521, 1588, 1657, 1727, 1729, 1801, 1876, 1953, 2196, 2198, 2743, 2745, 3155, 3374, 3376
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
REFERENCES
|
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
H. C. Williams and C. R. Zarnke, Computation of the solutions of the Diophantine equation x^3+dy^3=1, Proc. Conf. Numerical Maths., Winnipeg (1971), 671-676.
|
|
LINKS
|
|
|
MATHEMATICA
|
m = 400; s = {}; Do[If[x*y < 0, r = Reduce[ n > 0 && x^3 + n*y^3 == 1, n, Integers]; If[r =!= False, AppendTo[s, n /. ToRules[r]]]], {x, -m, m}, {y, -m, m}]; Union[s] [[1 ;; 38]] (* Jean-François Alcover, Jun 08 2011 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|