A042228 Numerators of continued fraction convergents to sqrt(640).

25, 76, 177, 253, 1189, 1442, 17051, 18493, 91023, 109516, 310055, 1039681, 52294105, 157921996, 368138097, 526060093, 2472378469, 2998438562, 35455202651, 38453641213, 189269767503, 227723408716, 644716584935, 2161873163521, 108738374760985, 328376997446476

Offset

0,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,0,0,0,0,0,0,2079362,0,0,0,0,0,0,0,0,0,0,0,-1).

Formula

G.f.: -(x^23 -25*x^22 +76*x^21 -177*x^20 +253*x^19 -1189*x^18 +1442*x^17 -17051*x^16 +18493*x^15 -91023*x^14 +109516*x^13 -310055*x^12 -1039681*x^11 -310055*x^10 -109516*x^9 -91023*x^8 -18493*x^7 -17051*x^6 -1442*x^5 -1189*x^4 -253*x^3 -177*x^2 -76*x -25) / ((x^6 -38*x^3 +1)*(x^6 +38*x^3 +1)*(x^12 +1442*x^6 +1)). - Colin Barker, Dec 04 2013

Mathematica

Numerator[Convergents[Sqrt[640], 30]] (* Harvey P. Dale, Jul 03 2013 *)

Crossrefs

Cf. A042229, A040614.

Sequence in context: A008852 A042226 A042224 * A042230 A189642 A221309

Adjacent sequences: A042225 A042226 A042227 * A042229 A042230 A042231

Keyword

nonn,frac,easy

Author

N. J. A. Sloane.

Extensions

More terms from Colin Barker, Dec 04 2013

Status

approved