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A173681 Number of ways of writing n as a sum of 8 nonnegative cubes. 12

%I #18 Aug 02 2017 10:36:13

%S 1,8,28,56,70,56,28,8,9,56,168,280,280,168,56,8,28,168,420,560,420,

%T 168,28,0,56,280,560,568,336,224,280,280,238,336,428,336,406,840,1120,

%U 840,392,224,168,224,840,1680,1680,840,196,56,28,280,1120,1680,1148,448,428,568,420,448,868,840,448,840,1689,1736,1008,616,616,336,476,1688,2576

%N Number of ways of writing n as a sum of 8 nonnegative cubes.

%C Order matters. This is the coefficient of q^n in the expansion of {Sum_{m>=0} q^(m^3)}^8.

%H Seiichi Manyama, <a href="/A173681/b173681.txt">Table of n, a(n) for n = 0..10000</a>

%H L. E. Dickson, <a href="http://dx.doi.org/10.1090/S0002-9904-1939-07041-9">All integers except 23 and 239 are sums of eight cubes</a>, Bull. Amer. Math. Soc. 45 (1939), 588-591.

%o (PARI) lista(n)=my(q='q); Vec(sum(m=0, (n+.5)^(1/3), q^(m^3), O(q^(n+1)))^8); \\ _Michel Marcus_, Apr 12 2016

%Y Cf. A004830, A173677.

%Y Sums of k cubes, number of ways of writing n as, for k=1..9: A010057, A173677, A051343, A173678, A173679, A173680, A173676, A173681, A173682.

%K nonn

%O 0,2

%A _N. J. A. Sloane_, Nov 25 2010

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