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A157787
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8984250n - 2515920.
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3
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6468330, 15452580, 24436830, 33421080, 42405330, 51389580, 60373830, 69358080, 78342330, 87326580, 96310830, 105295080, 114279330, 123263580, 132247830, 141232080, 150216330, 159200580, 168184830, 177169080, 186153330, 195137580
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| The identity (1482401250*n^2-830253600*n +116250751)^2-(27225*n^2-15248*n +2135) *(8984250*n -2515920)^2=1 can be written as A157788(n)^2-A157786(n)*a(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 (2,-1).
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FORMULA
| a(n) = 2*a(n-1) -a(n-2).
G.f: x*(6468330+2515920*x)/(x-1)^2.
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MATHEMATICA
| Table[8984250n-2515920, {n, 30}].
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PROG
| (MAGMA) I:=[6468330, 15452580]; [n le 2 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..30]];
(PARI) a(n) = 8984250*n - 2515920.
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CROSSREFS
| Cf. A157786, A157788.
Sequence in context: A018895 A178135 A141594 * A115615 A204404 A022237
Adjacent sequences: A157784 A157785 A157786 * A157788 A157789 A157790
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KEYWORD
| nonn,easy
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AUTHOR
| Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 06 2009
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