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A042484
Numerators of continued fraction convergents to sqrt(770).
2
27, 28, 83, 111, 6077, 6188, 18453, 24641, 1349067, 1373708, 4096483, 5470191, 299486797, 304956988, 909400773, 1214357761, 66484719867, 67699077628, 201882875123, 269581952751, 14759308323677, 15028890276428
OFFSET
0,1
FORMULA
G.f.: (27 +28*x +83*x^2 +111*x^3 +83*x^4 -28*x^5 +27*x^6 -x^7)/(1 -222*x^4 +x^8). - Vincenzo Librandi, Nov 26 2013
a(n) = 222*a(n-4) - a(n-8). - Vincenzo Librandi, Nov 26 2013
MATHEMATICA
Numerator[Convergents[Sqrt[770], 30]] (* or *) CoefficientList[Series[(27 + 28 x + 83 x^2 + 111 x^3 + 83 x^4 - 28 x^5 + 27 x^6 - x^7)/(1 - 222 x^4 + x^8), {x, 0, 30}], x] (* Vincenzo Librandi, Nov 25 2013 *)
PROG
(Magma) I:=[27, 28, 83, 111, 6077, 6188, 18453, 24641]; [n le 8 select I[n] else 222*Self(n-4)-Self(n-8): n in [1..30]]; // Vincenzo Librandi, Nov 26 2013
CROSSREFS
Cf. A042485.
Sequence in context: A141490 A242184 A042482 * A042480 A042478 A042476
KEYWORD
nonn,cofr,frac,easy
AUTHOR
STATUS
approved