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A041284
Numerators of continued fraction convergents to sqrt(155).
2
12, 25, 112, 249, 6088, 12425, 55788, 124001, 3031812, 6187625, 27782312, 61752249, 1509836288, 3081424825, 13835535588, 30752496001, 751895439612, 1534543375225, 6890068940512, 15314681256249
OFFSET
0,1
FORMULA
a(n) = 498*a(n-4)-a(n-8). - Vincenzo Librandi, Nov 01 2013
G.f.: (1+x)*(12 +13*x +99*x^2 +150*x^3 -38*x^4 +13*x^5 -x^6)/(1 -498*x^4 +x^8). [Bruno Berselli, Nov 01 2013]
MATHEMATICA
Numerator[Convergents[Sqrt[155], 30]] (* Vincenzo Librandi, Nov 01 2013 *)
LinearRecurrence[{0, 0, 0, 498, 0, 0, 0, -1}, {12, 25, 112, 249, 6088, 12425, 55788, 124001}, 20] (* Harvey P. Dale, Sep 13 2024 *)
PROG
(Magma) I:=[12, 25, 112, 249, 6088, 12425, 55788, 124001]; [n le 8 select I[n] else 498*Self(n-4)-Self(n-8): n in [1..25]]; // Vincenzo Librandi, Nov 01 2013
CROSSREFS
Cf. A041285.
Sequence in context: A042869 A041282 A195116 * A171069 A042193 A041286
KEYWORD
nonn,cofr,frac,easy
AUTHOR
STATUS
approved