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A157798
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1482401250n^2 - 658736100n + 73180801.
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3
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896845951, 4685313601, 11438583751, 21156656401, 33839531551, 49487209201, 68099689351, 89676972001, 114219057151, 141725944801, 172197634951, 205634127601, 242035422751, 281401520401, 323732420551, 369028123201, 417288628351
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| The identity(1482401250*n^2-658736100*n+73180801)^2-(27225*n^2-12098*n+1344)*(8984250*n-1996170)^2=1 can be written as a(n)^2-A157796(n)*A157797(n)^2=1.
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 1..10000
Vincenzo Librandi, X^2-AY^2=1
Index to sequences with linear recurrences with constant coefficients, signature (3,-3,1).
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FORMULA
| a(n) = 3*a(n-1) -3*a(n-2) +a(n-3).
G.f.: x*(-896845951-1994775748*x-73180801*x^2)/(x-1)^3.
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MATHEMATICA
| LinearRecurrence[{3, -3, 1}, {896845951, 4685313601, 11438583751}, 30]
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PROG
| (MAGMA) I:=[896845951, 4685313601, 11438583751]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+1*Self(n-3): n in [1..30]];
(PARI) a(n) = 1482401250*n^2 - 658736100*n + 73180801.
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CROSSREFS
| Cf. A157796, A157797.
Sequence in context: A204141 A183708 A178557 * A189229 A051470 A076135
Adjacent sequences: A157795 A157796 A157797 * A157799 A157800 A157801
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KEYWORD
| nonn,easy
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AUTHOR
| Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 07 2009
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