A002355 - OEIS

A002355

Denominators of convergents to cube root of 4.
(Formerly M1407 N0549)

1, 1, 2, 5, 12, 17, 63, 143, 492, 635, 2397, 3032, 93357, 96389, 478913, 575302, 1629517, 15240955, 93075247, 387541943, 480617190, 868159133, 2216935456, 16386707325, 34990350106, 121357757643, 277705865392, 399063623035, 2672087603602, 3071151226637

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OFFSET

0,3

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 = 0..999

MATHEMATICA

Denominator[Convergents[Power[4, (3)^-1], 30]] (* Vincenzo Librandi, Aug 24 2013 *)

PROG

(PARI) a(n) = contfracpnqn(contfrac(4^(1/3), n))[2, 1]; \\ Michel Marcus, Aug 23 2013

CROSSREFS

Cf. A002356 (numerators), A005480.

Sequence in context: A024465 A041889 A055906 * A085395 A041641 A131091

Adjacent sequences: A002352 A002353 A002354 * A002356 A002357 A002358

KEYWORD

nonn,frac

AUTHOR

N. J. A. Sloane, Herman P. Robinson

EXTENSIONS

More terms from Vincenzo Librandi, Aug 24 2013

Offset changed by Andrew Howroyd, Jul 04 2024

STATUS

approved