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12, 39, 66, 93, 120, 147, 174, 201, 228, 255, 282, 309, 336, 363, 390, 417, 444, 471, 498, 525, 552, 579, 606, 633, 660, 687, 714, 741, 768, 795, 822, 849, 876, 903, 930, 957, 984, 1011, 1038, 1065, 1092, 1119, 1146, 1173, 1200, 1227, 1254, 1281, 1308, 1335
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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COMMENTS
| The identity (81n^2+72n+17)^2-(9n^2+8n+2)*(27n+12)^2=1 can be written as A154295(n+1)^2-A154262(n+1)*a(n)^2=1. - Vincenzo Librandi, Feb 03 2012
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 0..10000
Index to sequences with linear recurrences with constant coefficients, signature (2,-1).
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FORMULA
| G.f.: 3*(4+5*x)/(x-1)^2. - R. J. Mathar, Jan 05 2011
a(n) = 3*A017209(n). - R. J. Mathar, Jan 05 2011
a(n) = 2*a(n-1)-a(n-2). - Vincenzo Librandi, Feb 02 2012
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MATHEMATICA
| Range[12, 7000, 27] (* From Vladimir Joseph Stephan Orlovsky, Jul 13 2011 *)
LinearRecurrence[{2, -1}, {12, 39}, 50] (* Vincenzo Librandi, Feb 02 2012 *)
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PROG
| (PARI) a(n)=27*n+12 \\ Charles R Greathouse IV, Dec 28 2011
(MAGMA) I:=[12, 39]; [n le 2 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..40]]; // Vincenzo Librandi, Feb 02 2012
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CROSSREFS
| Cf. A154262, A154295.
Sequence in context: A079539 A167712 A186779 * A119094 A139691 A114815
Adjacent sequences: A154263 A154264 A154265 * A154267 A154268 A154269
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KEYWORD
| nonn,easy,changed
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AUTHOR
| Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Jan 06 2009
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EXTENSIONS
| 119 replaced by 1119 - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 07 2009
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