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A042910
Numerators of continued fraction convergents to sqrt(987).
2
31, 63, 157, 377, 23531, 47439, 118409, 284257, 17742343, 35768943, 89280229, 214329401, 13377703091, 26969735583, 67317174257, 161604084097, 10086770388271, 20335144860639, 50757060109549, 121849265079737, 7605411495053243, 15332672255186223, 38270756005425689
OFFSET
0,1
LINKS
FORMULA
G.f.: (31 +63*x +157*x^2 +377*x^3 +157*x^4 -63*x^5 +31*x^6 -x^7)/(1 -754*x^4 +x^8). - Vincenzo Librandi, Dec 09 2013
a(n) = 754*a(n-4) - a(n-8). - Vincenzo Librandi, Dec 09 2013
MATHEMATICA
Numerator[Convergents[Sqrt[987], 20]] (* Harvey P. Dale, Mar 15 2013 *)
CoefficientList[Series[(31 + 63 x + 157 x^2 + 377 x^3 + 157 x^4 - 63 x^5 + 31 x^6 - x^7)/(1 - 754 x^4 + x^8), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 09 2013 *)
PROG
(Magma) I:=[31, 63, 157, 377, 23531, 47439, 118409, 284257]; [n le 8 select I[n] else 754*Self(n-4)-Self(n-8): n in [1..30]]; // Vincenzo Librandi, Dec 09 2013
CROSSREFS
Cf. A042911.
Sequence in context: A042902 A042900 A239128 * A042908 A042912 A167783
KEYWORD
nonn,cofr,frac,easy
AUTHOR
EXTENSIONS
More terms from Vincenzo Librandi, Dec 09 2013
STATUS
approved