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A211424
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Number of ordered triples (w,x,y) with all terms in {-n,...,0,...,n} and w^2+3*x*y=0.
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2
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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
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OFFSET
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0,2
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COMMENTS
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For a guide to related sequences, see A211422.
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LINKS
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Table of n, a(n) for n=0..52.
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MATHEMATICA
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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 *)
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CROSSREFS
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Cf. A211422.
Sequence in context: A087940 A092387 A175364 * A211428 A160720 A147552
Adjacent sequences: A211421 A211422 A211423 * A211425 A211426 A211427
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KEYWORD
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nonn
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AUTHOR
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Clark Kimberling, Apr 10 2012
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STATUS
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approved
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