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A157797
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8984250n - 1996170.
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3
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6988080, 15972330, 24956580, 33940830, 42925080, 51909330, 60893580, 69877830, 78862080, 87846330, 96830580, 105814830, 114799080, 123783330, 132767580, 141751830, 150736080, 159720330, 168704580, 177688830, 186673080, 195657330
(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 A157798(n)^2-A157796(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*(6988080+1996170*x)/(x-1)^2.
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MATHEMATICA
| LinearRecurrence[{2, -1}, {6988080, 15972330}, 30]
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PROG
| (MAGMA) I:=[6988080, 15972330]; [n le 2 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..30]];
(PARI) a(n) = 8984250*n - 1996170.
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CROSSREFS
| Cf. A157796, A157798.
Sequence in context: A185427 A185426 A186793 * A106786 A206634 A088286
Adjacent sequences: A157794 A157795 A157796 * A157798 A157799 A157800
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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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