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A041595
Denominators of continued fraction convergents to sqrt(315).
2
1, 1, 3, 4, 139, 143, 425, 568, 19737, 20305, 60347, 80652, 2802515, 2883167, 8568849, 11452016, 397937393, 409389409, 1216716211, 1626105620, 56504307291, 58130412911, 172765133113, 230895546024, 8023213697929, 8254109243953, 24531432185835, 32785541429788
OFFSET
0,3
FORMULA
G.f.: -(x^2-x-1)*(x^4+4*x^2+1) / ((x^4-12*x^2+1)*(x^4+12*x^2+1)). - Colin Barker, Nov 19 2013
a(n) = 142*a(n-4) - a(n-8) for n>7, - Vincenzo Librandi, Dec 21 2013
MATHEMATICA
Denominator[Convergents[Sqrt[315], 30]] (* Vincenzo Librandi, Dec 21 2013 *)
PROG
(Magma) I:=[1, 1, 3, 4, 139, 143, 425, 568]; [n le 8 select I[n] else 142*Self(n-4)-Self(n-8): n in [1..40]]; // Vincenzo Librandi, Dec 21 2013
CROSSREFS
Sequence in context: A331815 A077032 A370385 * A041741 A041903 A156513
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Nov 19 2013
STATUS
approved