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A010057
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a(n) = 1 if n is a cube, else 0.
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79
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1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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0,1
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COMMENTS
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Multiplicative with a(p^e) = 1 if 3 divides e, 0 otherwise. - Mitch Harris, Jun 09 2005
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REFERENCES
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E. Landau, Elementary Number Theory, translation by Jacob E. Goodman of Elementare Zahlentheorie (Vol. I_1 (1927) of Vorlesungen ueber Zahlentheorie), by Edmund Landau, with added exercises by Paul T. Bateman and E. E. Kohlbecker, Chelsea Publishing Co., New York, 1958, pp. 31-32.
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LINKS
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FORMULA
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a(n) = f(n,0) with f(x,y) = if x>0 then f(x-3*y*(y+1),y+1) else 0^(-x). - Reinhard Zumkeller, Sep 27 2008
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MAPLE
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if n = 0 then
1;
else
for pe in ifactors(n)[2] do
if modp(op(2, pe), 3) <> 0 then
return 0 ;
end if;
end do:
end if;
1 ;
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MATHEMATICA
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PROG
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(Haskell)
a010057 0 = 1
a010057 n = fromEnum $ all ((== 0) . (`mod` 3)) $ a124010_row n
a010057_list = concatMap (\x -> 1 : replicate (a003215 x - 1) 0) [0..]
(Python)
from sympy import integer_nthroot
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CROSSREFS
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KEYWORD
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nonn,easy,mult
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AUTHOR
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STATUS
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approved
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