A017983 Powers of cube root of 3 rounded to nearest integer.

1, 1, 2, 3, 4, 6, 9, 13, 19, 27, 39, 56, 81, 117, 168, 243, 350, 505, 729, 1051, 1516, 2187, 3154, 4549, 6561, 9463, 13647, 19683, 28388, 40942, 59049, 85163, 122827, 177147, 255490, 368481, 531441, 766471, 1105442, 1594323, 2299412, 3316325, 4782969, 6898235

Offset

0,3

Links

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

Mathematica

Table[Round[3^(n/3)], {n, 0, 50}] (* Vincenzo Librandi, Jan 07 2014 *)
Round[CubeRoot[3]^Range[0, 50]] (* Harvey P. Dale, Jul 21 2023 *)

Prog

(Magma) [Round(3^(n/3)): n in [0..50]]; // Vincenzo Librandi, Jan 07 2014
(Python)
from sympy import integer_nthroot
def A017983(n): return -integer_nthroot(m:=3**n, 3)[0]+integer_nthroot(m<<3, 3)[0] # Chai Wah Wu, Jun 18 2024

Crossrefs

Cf. powers of cube root of k rounded up: A017980 (k=2), this sequence (k=3), A017986 (k=4), A017989 (k=5), A017992 (k=6), A017995 (k=7), A018001 (k=9), A018004 (k=10), A018007 (k=11), A018010 (k=12), A018013 (k=13), A018016 (k=14), A018019 (k=15), A018022 (k=16), A018025 (k=17), A018028 (k=18), A018031 (k=19), A018034 (k=20), A018037 (k=21), A018040 (k=22), A018043 (k=23), A018046 (k=24).

Sequence in context: A003143 A221718 A251571 * A139077 A017825 A247083

Adjacent sequences: A017980 A017981 A017982 * A017984 A017985 A017986

Keyword

nonn

Author

N. J. A. Sloane.

Extensions

More terms from Vincenzo Librandi, Jan 07 2014

Status

approved