%I #16 Aug 15 2024 11:55:36
%S 0,1,8,27,64,125,216,343,512,729,1,8,27,64,125,216,343,512,729,1000,8,
%T 27,64,125,216,343,512,729,1000,1331,27,64,125,216,343,512,729,1000,
%U 1331,1728,64,125,216,343,512,729,1000,1331,1728,2197,125,216,343,512
%N a(n) is the cube of the sum of digits of n.
%F a(n) = (A007953(n))^3. - _R. J. Mathar_, Apr 22 2010
%e Trajectories of x->a(x), see A182128:
%e 1 ->1 ->1 ->1 ->1 ->1 ->1 ->1 ->1 ->...
%e 2 ->8 ->512 ->512 ->512 ->512 ->512 ->512 ->512 ->...
%e 3 ->27 ->729 ->5832 ->5832 ->5832 ->5832 ->5832 ->5832 ->...
%e 4 ->64 ->1000 ->1 ->1 ->1 ->1 ->1 ->1 ->...
%e 5 ->125 ->512 ->512 ->512 ->512 ->512 ->512 ->512 ->...
%e 6 ->216 ->729 ->5832 ->5832 ->5832 ->5832 ->5832 ->5832 ->...
%e 7 ->343 ->1000 ->1 ->1 ->1 ->1 ->1 ->1 ->...
%e 8 ->512 ->512 ->512 ->512 ->512 ->512 ->512 ->512 ->...
%e 9 ->729 ->5832 ->5832 ->5832 ->5832 ->5832 ->5832 ->5832 ->...
%e 10 ->1 ->1 ->1 ->1 ->1 ->1 ->1 ->1 ->...
%e 11 ->8 ->512 ->512 ->512 ->512 ->512 ->512 ->512 ->...
%e 12 ->27 ->729 ->5832 ->5832 ->5832 ->5832 ->5832 ->5832 ->...
%e 13 ->64 ->1000 ->1 ->1 ->1 ->1 ->1 ->1 ->...
%e 14 ->125 ->512 ->512 ->512 ->512 ->512 ->512 ->512 ->...
%e - _R. J. Mathar_, Jul 08 2012
%t a[n_]:=DigitSum[n]^3; Array[a,54,0] (* _Stefano Spezia_, Aug 15 2024 *)
%o (Python)
%o def a(n): return sum(map(int, str(n)))**3
%o print([a(n) for n in range(54)]) # _Michael S. Branicky_, Dec 26 2021
%Y Cf. A007953, A182128.
%K base,easy,nonn
%O 0,3
%A _Giovanni Teofilatto_, May 25 2006
%E Name and offset corrected by _Jon E. Schoenfield_, Dec 26 2021