A042238 Numerators of continued fraction convergents to sqrt(645).

25, 51, 76, 127, 1600, 16127, 195124, 211251, 406375, 1024001, 51606425, 104236851, 155843276, 260080127, 3276804800, 33028128127, 399614342324, 432642470451, 832256812775, 2097156096001, 105690061612825, 213477279321651, 319167340934476, 532644620256127

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, 2048002, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1).

Formula

G.f.: -(x^19 -25*x^18 +51*x^17 -76*x^16 +127*x^15 -1600*x^14 +16127*x^13 -195124*x^12 +211251*x^11 -406375*x^10 -1024001*x^9 -406375*x^8 -211251*x^7 -195124*x^6 -16127*x^5 -1600*x^4 -127*x^3 -76*x^2 -51*x -25) / (x^20 -2048002*x^10 +1). - Colin Barker, Dec 05 2013

Mathematica

Numerator[Convergents[Sqrt[645], 30]] (* Vincenzo Librandi, Nov 19 2013 *)

Crossrefs

Cf. A042239, A040619.

Sequence in context: A034025 A253017 A042236 * A042234 A042232 A273868

Adjacent sequences: A042235 A042236 A042237 * A042239 A042240 A042241

Keyword

nonn,cofr,frac,easy

Author

N. J. A. Sloane.

Extensions

More terms from Colin Barker, Dec 05 2013

Status

approved