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210, 885, 2010, 3585, 5610, 8085, 11010, 14385, 18210, 22485, 27210, 32385, 38010, 44085, 50610, 57585, 65010, 72885, 81210, 89985, 99210, 108885, 119010, 129585, 140610, 152085, 164010, 176385, 189210, 202485, 216210, 230385, 245010, 260085
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| The identity (30*n^2-1)^2-(225*n^2-15) * (2*n)^2 = 1 can be written as A158560(n)^2 - a(n) * A005843(n)^2 =1.
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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
| G.f.: 15*x*(-14-17*x+x^2)/(x-1)^3.
a(n)= 3*a(n-1) -3*a(n-2) +a(n-3).
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MATHEMATICA
| 15(15Range[40]^2-1) (* or *) LinearRecurrence[{3, -3, 1}, {210, 885, 2010}, 40] (* From Harvey P. Dale, Jan 24 2012 *)
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PROG
| (MAGMA) I:=[210, 885, 2010]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+1*Self(n-3): n in [1..50]]; // Vincenzo Librandi, Feb 14 2012
(PARI) for(n=1, 40, print1(225*n^2 - 15", ")); \\ Vincenzo Librandi, Feb 05 2012
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CROSSREFS
| Cf. A005843, A158560.
Sequence in context: A118279 A163263 A009127 * A046302 A157408 A118281
Adjacent sequences: A158556 A158557 A158558 * A158560 A158561 A158562
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KEYWORD
| nonn,easy,changed
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AUTHOR
| Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 21 2009
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EXTENSIONS
| Comment rewritten - R. J. Mathar, Oct 16 2009
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