This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A211424 Number of ordered triples (w,x,y) with all terms in {-n,...,0,...,n} and w^2+3*x*y=0. 2
 1, 5, 9, 21, 25, 29, 49, 53, 57, 69, 73, 77, 105, 109, 113, 125, 137, 141, 161, 165, 169, 181, 185, 189, 217, 229, 233, 261, 265, 269, 297, 301, 313, 325, 329, 333, 369, 373, 377, 389, 393, 397, 417, 421, 425, 445, 449, 453, 497, 517, 529, 541, 545 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS For a guide to related sequences, see A211422. LINKS MATHEMATICA t[n_] := t[n] = Flatten[Table[w^2 + 3 x*y, {w, -n, n}, {x, -n, n}, {y, -n, n}]] c[n_] := Count[t[n], 0] t = Table[c[n], {n, 0, 70}]  (* A211424 *) (t - 1)/4                    (* integers  *) CROSSREFS Cf. A211422. Sequence in context: A087940 A092387 A175364 * A211428 A160720 A147552 Adjacent sequences:  A211421 A211422 A211423 * A211425 A211426 A211427 KEYWORD nonn AUTHOR Clark Kimberling, Apr 10 2012 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .