A041473 Denominators of continued fraction convergents to sqrt(252).

1, 1, 7, 8, 247, 255, 1777, 2032, 62737, 64769, 451351, 516120, 15934951, 16451071, 114641377, 131092448, 4047414817, 4178507265, 29118458407, 33296965672, 1028027428567, 1061324394239, 7395973794001, 8457298188240, 261114919441201, 269572217629441

Offset

0,3

Links

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

Index entries for linear recurrences with constant coefficients, signature (0,0,0,254,0,0,0,-1).

Formula

G.f.: -(x^2-x-1)*(x^4+8*x^2+1) / ((x^4-16*x^2+1)*(x^4+16*x^2+1)). - Colin Barker, Nov 18 2013

a(n) = 254*a(n-4) - a(n-8) for n>7. - Vincenzo Librandi, Dec 18 2013

Mathematica

Denominator[Convergents[Sqrt[252], 30]] (* Vincenzo Librandi, Dec 18 2013 *)

Prog

(Magma) I:=[1, 1, 7, 8, 247, 255, 1777, 2032]; [n le 8 select I[n] else 254*Self(n-4)-Self(n-8): n in [1..40]]; // Vincenzo Librandi, Dec 18 2013

Crossrefs

Cf. A041472, A040236.

Sequence in context: A041110 A041259 A371104 * A041751 A042093 A042499

Adjacent sequences: A041470 A041471 A041472 * A041474 A041475 A041476

Keyword

nonn,frac,easy

Author

N. J. A. Sloane.

Extensions

More terms from Colin Barker, Nov 18 2013

Status

approved