A041760 Numerators of continued fraction convergents to sqrt(401).

20, 801, 32060, 1283201, 51360100, 2055687201, 82278848140, 3293209612801, 131810663360180, 5275719744020001, 211160600424160220, 8451699736710428801, 338279150068841312260, 13539617702490362919201, 541922987249683358080300

Offset

0,1

Links

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

Tanya Khovanova, Recursive Sequences

Index entries for linear recurrences with constant coefficients, signature (40,1).

Formula

a(n) = 40*a(n-1)+a(n-2) for n>1, a(0)=20, a(1)=801. G.f.: (20+x)/(1-40*x-x^2). [Philippe Deléham, Nov 23 2008]

Mathematica

Numerator[Convergents[Sqrt[401], 30]] (* Vincenzo Librandi, Nov 07 2013 *)

Crossrefs

Cf. A041761, A040380.

Sequence in context: A267671 A281777 A041763 * A250550 A292417 A117798

Adjacent sequences: A041757 A041758 A041759 * A041761 A041762 A041763

Keyword

nonn,cofr,frac,easy,less

Author

N. J. A. Sloane.

Status

approved