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A047702 Numbers that are the sum of 3 but no fewer positive cubes. 4

%I

%S 3,10,17,24,29,36,43,55,62,66,73,80,81,92,99,118,127,129,134,136,141,

%T 153,155,160,179,190,192,197,218,225,232,244,251,253,258,270,277,281,

%U 288,307,314,342,345,349,352,359,368,371,375,378,397,405,408,415,433

%N Numbers that are the sum of 3 but no fewer positive cubes.

%D C. G. J. Jacobi, Gesammelte Werke, vol. 6, 1969, Chelsea, NY, p. 352.

%H T. D. Noe, <a href="/A047702/b047702.txt">Table of n, a(n) for n=1..1000</a>

%H C. G. J. Jacobi, <a href="http://www.hti.umich.edu/cgi/t/text/text-idx?c=umhistmath;idno=ABR8803">Gesammelte Werke</a>.

%H <a href="/index/Su#ssq">Index entries for sequences related to sums of cubes</a>

%F The numbers in {A003072 MINUS A000578} MINUS A003325. - _R. J. Mathar_, Apr 13 2008

%e 344 is in A003072, but also in A003325; therefore it is not in here.

%p N:= 1000: # to get all terms <= N

%p G3:= series(add(x^(i^3),i=1..floor(N^(1/3)))^3,x,N+1):

%p G2:= series(add(x^(i^3),i=0..floor(N^(1/3)))^2,x,N+1):

%p select(t -> coeff(G3,x,t) > 0 and coeff(G2,x,t) = 0, [$1..N]); # _Robert Israel_, Dec 12 2016

%t Select[Range[500], (pr = PowersRepresentations[#, 3, 3]; pr != {} && Count[pr, r_ /; (Times @@ r) == 0] == 0) &][[1 ;; 55]] (* _Jean-Fran├žois Alcover_, Apr 08 2011 *)

%Y Cf. A000419, A002376, A003072.

%K nonn,nice,easy

%O 1,1

%A Arlin Anderson (starship1(AT)gmail.com)

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Last modified November 17 18:24 EST 2019. Contains 329241 sequences. (Running on oeis4.)