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5, 29, 69, 125, 197, 285, 389, 509, 645, 797, 965, 1149, 1349, 1565, 1797, 2045, 2309, 2589, 2885, 3197, 3525, 3869, 4229, 4605, 4997, 5405, 5829, 6269, 6725, 7197, 7685, 8189, 8709, 9245, 9797, 10365, 10949, 11549, 12165, 12797, 13445, 14109, 14789
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Sequence found by reading the segment (5, 29) together with the line from 29, in the direction 29, 69,..., in the square spiral whose vertices are the triangular numbers A000217. - Omar E. Pol, Sep 04 2011
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 1..10000
Index to sequences with linear recurrences with constant coefficients, signature (3,-3,1).
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FORMULA
| a(n) = 2*(2*n-1)*(2*n+1)-1.
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EXAMPLE
| (1*3 = 3)+2 = 5; (3*5 = 15)+14 = 29; (5*7 = 35)+34 = 69; (7*9 = 63)+62 = 125; ...
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MAPLE
| seq(8*n^2-3, n=1..50); (Emeric Deutsch)
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PROG
| (PARI) a(n)=8*n^2-3 \\ Charles R Greathouse IV, Sep 04 2011
(MAGMA) [8*n^2 - 3: n in [1..50]]; // Vincenzo Librandi, Sep 05 2011
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CROSSREFS
| Sequence in context: A115706 A031394 A103094 * A097812 A176333 A100559
Adjacent sequences: A108925 A108926 A108927 * A108929 A108930 A108931
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KEYWORD
| easy,nonn
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AUTHOR
| Marcel Hetkowski Fabeny (marcelfabeny(AT)yahoo.com.br), Jul 19 2005
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EXTENSIONS
| More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Aug 01 2005
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