A185550 - OEIS

%I #11 Sep 10 2024 00:25:05

%S 2,4,5,7,9,10,11,13,14,16,17,18,20,21,22,24,25,26,28,29,30,31,33,34,

%T 35,36,38,39,40,41,43,44,45,46,48,49,50,51,52,54,55,56,57,58,60,61,62,

%U 63,65,66,67,68,69,70,72,73,74,75,76,78,79,80,81,82,84,85,86,87,88,89,91,92,93,94,95,96,98,99,100,101,102,103,105,106,107,108,109,110,112,113,114,115,116,117,119,120,121,122,123,124,126,127,128,129,130,131,132,134,135,136,137,138,139,140,142,143,144,145,146,147,148,150

%N Numbers not of the form ceiling(n^(3/2)); complement of A185549.

%H Reinhard Zumkeller, <a href="/A185550/b185550.txt">Table of n, a(n) for n = 1..10000</a>

%t f[n_]=Ceiling[n^(3/2)];

%t t1=Table[f[n],{n,1,90}];t1  (* A185549 *)

%t t2=Complement[Range[150], Table[f[n],{n,1,80}]];t2  (* A185550 *)

%o (Haskell)

%o import Data.List.Ordered (minus)

%o a185550 n = a185550_list !! (n-1)

%o a185550_list = [0..] `minus` a185549_list

%o -- _Reinhard Zumkeller_, Jul 24 2015

%o (Python)

%o from sympy import integer_nthroot

%o def A185550(n):

%o     def f(x): return n+integer_nthroot(x**2,3)[0]

%o     def iterfun(f,n=0):

%o         m, k = n, f(n)

%o         while m != k: m, k = k, f(k)

%o         return m

%o     return iterfun(f,n) # _Chai Wah Wu_, Sep 09 2024

%Y Cf. A185549, A185543.

%K nonn

%O 1,1

%A _Clark Kimberling_, Jan 30 2011