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A173677
Number of ways of writing n as a sum of two nonnegative cubes.
14
1, 2, 1, 0, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 0, 0, 2, 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, 2, 2, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 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, 2
OFFSET
0,2
COMMENTS
Order matters. This is the coefficient of q^n in the expansion of {Sum_{m>=0} q^(m^3)}^2.
LINKS
FORMULA
a(n) = Sum_{k=0..n} c(k) * c(n-k), where c = A010057. - Wesley Ivan Hurt, Nov 09 2023
PROG
(PARI) list(n)=my(q='q); Vec(sum(m=0, (n+.5)^(1/3), q^(m^3), O(q^(n+1)))^2) \\ Charles R Greathouse IV, Jun 07 2012
CROSSREFS
Sums of k cubes, number of ways of writing n as, for k=1..9: A010057, A173677, A051343, A173678, A173679, A173680, A173676, A173681, A173682.
Sequence in context: A350750 A154234 A091396 * A219480 A277627 A037857
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Nov 24 2010
STATUS
approved