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0, 1, 1, 1, 1, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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0,6
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COMMENTS
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apart from 0, k^3 occurs 3*n^2+1 times, cf. A056107.
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LINKS
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FORMULA
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G.f.: (1-x)^(-1)*Sum_{k>=0} (3*k^2+3*k+1)*x^((k+1)*(k^2+k/2+1)). - Robert Israel, Jan 03 2017
Sum_{n>=1} 1/a(n)^2 = Pi^4/30 + Pi^6/945. - Amiram Eldar, Aug 15 2022
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MAPLE
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MATHEMATICA
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Module[{nn=70, c}, c=Range[0, Ceiling[Surd[nn, 3]]]^3; Flatten[Array[ Nearest[ c, #]&, nn, 0]]] (* Harvey P. Dale, May 27 2014 *)
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PROG
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(Haskell)
a201053 n = a201053_list !! n
a201053_list = 0 : concatMap (\x -> replicate (a056107 x) (x ^ 3)) [1..]
(Python)
from sympy import integer_nthroot
a = integer_nthroot(n, 3)[0]
return a**3 if 2*n < a**3+(a+1)**3 else (a+1)**3 # Chai Wah Wu, Mar 31 2021
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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