A002358 Numerators of convergents to cube root of 5.

1, 2, 5, 12, 53, 171, 566, 737, 4251, 4988, 9239, 41944, 428679, 7329487, 7758166, 115943811, 123701977, 239645788, 731522646953, 731762292741, 1463284939694, 2195047232435, 3658332172129, 5853379404564, 9511711576693, 24876802557950, 59265316692593

Offset: 0

Author

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

Keywords

• nonn
• frac

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

Crossrefs

Cf. A002357 (denominators), A005481.

Programs

Mathematica

Numerator[Convergents[5^(1/3), 30]] (* Vincenzo Librandi, Sep 08 2013 *)

PARI

a(n)= contfracpnqn(contfrac(5^(1/3), n))[1, 1]; \\ Michel Marcus, Sep 07 2013

Extensions

More terms from Vincenzo Librandi, Sep 08 2013