A002356 Numerators of convergents to cube root of 4. (Formerly M0881 N0335)

1, 2, 3, 8, 19, 27, 100, 227, 781, 1008, 3805, 4813, 148195, 153008, 760227, 913235, 2586697, 24193508, 147747745, 615184488, 762932233, 1378116721, 3519165675, 26012276446, 55543718567, 192643432147, 440830582861, 633474015008, 4241674672909, 4875148687917

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

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

Prog

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

Crossrefs

Cf. A002355, A005480.

Sequence in context: A273754 A242099 A041205 * A166302 A347736 A100342

Adjacent sequences: A002353 A002354 A002355 * A002357 A002358 A002359

Keyword

nonn,frac

Author

N. J. A. Sloane

Extensions

More terms from Herman P. Robinson

More terms from Vincenzo Librandi, Aug 24 2013

Status

approved