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14, 60, 138, 248, 390, 564, 770, 1008, 1278, 1580, 1914, 2280, 2678, 3108, 3570, 4064, 4590, 5148, 5738, 6360, 7014, 7700, 8418, 9168, 9950, 10764, 11610, 12488, 13398, 14340, 15314, 16320, 17358, 18428, 19530, 20664, 21830, 23028, 24258, 25520
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| The identity (16*(n-1)+15)^2-(16*n^2-2*n)*4^2=1 can be written as A125169(n-1)^2-a(n)*4^2=1. - Vincenzo Librandi, Feb 01 2012
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 1..10000
E. J. Barbeau, Polynomial Excursions, Chapter 10: Diophantine equations (2010), pages 84-85 (row 15 in the first table at p. 85, case d(t) = t*(4^2*t-2)).
Index to sequences with linear recurrences with constant coefficients, signature (3,-3,1).
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FORMULA
| G.f.: x*(-14-18*x)/(x-1)^3.
a(n) = 3*a(n-1) -3*a(n-2) +a(n-3).
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MAPLE
| seq(16*n^2-2*n, n=1..40); # Nathaniel Johnston, Jun 26 2011
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MATHEMATICA
| LinearRecurrence[{3, -3, 1}, {14, 60, 138}, 40]
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PROG
| (MAGMA) [16*n^2-2*n: n in [1..40]]
(PARI) a(n) = 16*n^2-2*n.
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CROSSREFS
| Cf. A125169.
Sequence in context: A100174 A120371 A062022 * A100171 A063492 A051799
Adjacent sequences: A158055 A158056 A158057 * A158059 A158060 A158061
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KEYWORD
| nonn,easy,changed
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AUTHOR
| Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 12 2009
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