A002361 Denominators of convergents to fifth root of 2. (Formerly M4062 N1684)

1, 6, 7, 20, 27, 47, 74, 269, 6799, 7068, 35071, 112281, 371914, 2715679, 141587222, 144302901, 430193024, 1434881973, 3299956970, 50934236523, 105168430016, 261271096555, 1150252816236, 18665316156331, 38480885128898, 288031512058617, 326512397187515

Offset

1,2

References

D. H. Lehmer, Guide to Tables in the Theory of Numbers. Bulletin No. 105, National Research Council, Washington, DC, 1941, p. 67.

P. Seeling, Verwandlung der irrationalen Groesse ... in einen Kettenbruch, Archiv. Math. Phys., 46 (1866), 80-120.

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Mathematica

Denominator[Convergents[2^(1/5), 30]] (* Harvey P. Dale, Apr 27 2012 *)

Prog

(PARI) a(n)= contfracpnqn(contfrac(2^(1/5), n))[2, 1]; \\ Michel Marcus, Sep 07 2013

Crossrefs

Cf. A002362, A005531.

Sequence in context: A175262 A345911 A081348 * A041185 A042389 A287859

Adjacent sequences: A002358 A002359 A002360 * A002362 A002363 A002364

Keyword

nonn,frac

Author

N. J. A. Sloane

Extensions

More terms from Herman P. Robinson

Definition clarified and more terms from Harvey P. Dale, Apr 27 2012

Status

approved