A018046 - OEIS

%I #19 Jun 18 2024 21:04:24

%S 1,3,8,24,69,200,576,1661,4793,13824,39875,115020,331776,957008,

%T 2760488,7962624,22968182,66251701,191102976,551236370,1590040836,

%U 4586471424,13229672881,38160980056,110075314176,317512149144,915863521339,2641807540224,7620291579446

%N Powers of cube root of 24 rounded to nearest integer.

%H Vincenzo Librandi, <a href="/A018046/b018046.txt">Table of n, a(n) for n = 0..300</a>

%t Floor[(Power[24,(3)^-1])^Range[0,30]+1/2] (* _Harvey P. Dale_, Nov 13 2011 *)

%t Table[Round[24^(n/3)], {n, 0, 40}] (* _Vincenzo Librandi_, Jan 09 2014 *)

%o (Magma) [Round(24^(n/3)): n in [0..40]]; // _Vincenzo Librandi_, Jan 09 2014

%o (Python)

%o from sympy import integer_nthroot

%o def A018046(n): return -integer_nthroot(m:=3**n<<3*n,3)[0]+integer_nthroot(m<<3,3)[0] # _Chai Wah Wu_, Jun 18 2024

%Y Cf. powers of cube root of k rounded up: A017980 (k=2), A017983 (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), this sequence (k=24).

%K nonn

%O 0,2

%A _N. J. A. Sloane_

%E More terms from _Vincenzo Librandi_, Jan 09 2014