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A041154
Numerators of continued fraction convergents to sqrt(87).
2
9, 28, 513, 1567, 28719, 87724, 1607751, 4910977, 90005337, 274926988, 5038691121, 15391000351, 282076697439, 861621092668, 15791256365463, 48235390189057, 884028279768489, 2700320229494524, 49489792410669921
OFFSET
0,1
FORMULA
G.f.: (9 + 28*x + 9*x^2 - x^3) / (1 - 56*x^2 + x^4). [Bruno Berselli, Oct 29 2013]
a(n) = 56*a(n-2) - a(n-4). [Bruno Berselli, Oct 29 2013]
MATHEMATICA
Numerator[Convergents[Sqrt[87], 30]] (* Vincenzo Librandi, Oct 29 2013 *)
CROSSREFS
Sequence in context: A271185 A306843 A277511 * A024121 A205144 A258483
KEYWORD
nonn,cofr,frac,easy
AUTHOR
STATUS
approved