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A042514 Numerators of continued fraction convergents to sqrt(786). 2
28, 785, 43988, 1232449, 69061132, 1934944145, 108425933252, 3037861075201, 170228646144508, 4769439953121425, 267258866020944308, 7488017688539562049, 419596249424236419052, 11756183001567159295505 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,1
LINKS
FORMULA
a(n) = (28 + 785*x + 28*x^2 - x^3)/(1 - 1570*x^2 + x^4). - Vincenzo Librandi, Nov 26 2013
a(n) = 1570*a(n-2) - a(n-4). - Vincenzo Librandi, Nov 26 2013
MATHEMATICA
Numerator[Convergents[Sqrt[786], 30]] (* or *) CoefficientList[Series[(28 + 785 x + 28 x^2 - x^3)/(1 - 1570 x^2 + x^4), {x, 0, 30}], x] (* Vincenzo Librandi, Nov 25 2013 *)
LinearRecurrence[{0, 1570, 0, -1}, {28, 785, 43988, 1232449}, 20] (* Harvey P. Dale, Feb 24 2015 *)
PROG
(Magma) I:=[28, 785, 43988, 1232449]; [n le 4 select I[n] else 1570*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Nov 26 2013
CROSSREFS
Cf. A042515.
Sequence in context: A009972 A114037 A041365 * A158659 A214133 A119055
KEYWORD
nonn,cofr,frac,easy
AUTHOR
STATUS
approved

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Last modified April 17 09:46 EDT 2024. Contains 371763 sequences. (Running on oeis4.)