A118880 a(n) is the cube of the sum of digits of n.
0, 1, 8, 27, 64, 125, 216, 343, 512, 729, 1, 8, 27, 64, 125, 216, 343, 512, 729, 1000, 8, 27, 64, 125, 216, 343, 512, 729, 1000, 1331, 27, 64, 125, 216, 343, 512, 729, 1000, 1331, 1728, 64, 125, 216, 343, 512, 729, 1000, 1331, 1728, 2197, 125, 216, 343, 512
Offset: 0
Examples
Trajectories of x->a(x), see A182128: 1 ->1 ->1 ->1 ->1 ->1 ->1 ->1 ->1 ->... 2 ->8 ->512 ->512 ->512 ->512 ->512 ->512 ->512 ->... 3 ->27 ->729 ->5832 ->5832 ->5832 ->5832 ->5832 ->5832 ->... 4 ->64 ->1000 ->1 ->1 ->1 ->1 ->1 ->1 ->... 5 ->125 ->512 ->512 ->512 ->512 ->512 ->512 ->512 ->... 6 ->216 ->729 ->5832 ->5832 ->5832 ->5832 ->5832 ->5832 ->... 7 ->343 ->1000 ->1 ->1 ->1 ->1 ->1 ->1 ->... 8 ->512 ->512 ->512 ->512 ->512 ->512 ->512 ->512 ->... 9 ->729 ->5832 ->5832 ->5832 ->5832 ->5832 ->5832 ->5832 ->... 10 ->1 ->1 ->1 ->1 ->1 ->1 ->1 ->1 ->... 11 ->8 ->512 ->512 ->512 ->512 ->512 ->512 ->512 ->... 12 ->27 ->729 ->5832 ->5832 ->5832 ->5832 ->5832 ->5832 ->... 13 ->64 ->1000 ->1 ->1 ->1 ->1 ->1 ->1 ->... 14 ->125 ->512 ->512 ->512 ->512 ->512 ->512 ->512 ->... - _R. J. Mathar_, Jul 08 2012
Programs
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Mathematica
a[n_]:=DigitSum[n]^3; Array[a,54,0] (* Stefano Spezia, Aug 15 2024 *)
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Python
def a(n): return sum(map(int, str(n)))**3 print([a(n) for n in range(54)]) # Michael S. Branicky, Dec 26 2021
Formula
a(n) = (A007953(n))^3. - R. J. Mathar, Apr 22 2010
Extensions
Name and offset corrected by Jon E. Schoenfield, Dec 26 2021