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A118880
a(n) is the cube of the sum of digits of n.
3
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
0,3
FORMULA
a(n) = (A007953(n))^3. - R. J. Mathar, Apr 22 2010
EXAMPLE
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
MATHEMATICA
a[n_]:=DigitSum[n]^3; Array[a, 54, 0] (* Stefano Spezia, Aug 15 2024 *)
PROG
(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
CROSSREFS
Sequence in context: A376270 A055012 A069939 * A048390 A000578 A062292
KEYWORD
base,easy,nonn
AUTHOR
Giovanni Teofilatto, May 25 2006
EXTENSIONS
Name and offset corrected by Jon E. Schoenfield, Dec 26 2021
STATUS
approved