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Search: id:A132209
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| A132209 |
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Sequence gives X values from solving the equation 2*X^3 + 3*X^2 = Y^2. |
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+0
6
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| 0, 3, 11, 23, 39, 59, 83, 111, 143, 179, 219, 263, 311, 363, 419, 479, 543, 611, 683, 759, 839, 923, 1011, 1103, 1199, 1299, 1403, 1511, 1623, 1739, 1859, 1983, 2111, 2243, 2379, 2519, 2663, 2811, 2963, 3119
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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Essentially identical to A142463.
To find Y values: b(n)=(2*n^2 + 2n - 1)(2n - 1).
Except for the first term, a(n)=4*n+a(n-1) (with a(1)=3) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Nov 28 2009]
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FORMULA
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a(n)=2*n^2 + 2n - 1, with n>=1.
G.f.: x*(1+x)*(3-x)/(1-x)^3. - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 14 2007
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CROSSREFS
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Cf. A005563, A046092, A001082, A002378, A036666, A062717, A028347, A087475, A000217.
Cf. A153238 [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Jan 03 2009]
Sequence in context: A072671 A119173 A106201 this_sequence A142463 A086497 A121509
Adjacent sequences: A132206 A132207 A132208 this_sequence A132210 A132211 A132212
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KEYWORD
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nonn,new
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AUTHOR
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Mohamed Bouhamida (bhmd95(AT)yahoo.fr), Nov 06 2007
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EXTENSIONS
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Edited by the Associate Editors of the OEIS, Nov 15 2009
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