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A181402
Total number of positive integers below 10^n requiring 7 positive cubes in their representation as sum of cubes.
9
1, 10, 73, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121, 121
OFFSET
1,2
COMMENTS
An unpublished result of Deshouillers-Hennecart-Landreau, combined with Lemma 3 from Bertault, Ramaré, & Zimmermann implies that a(4)-a(34) are all 121. Probably a(n) = 121 for all n > 3. - Charles R Greathouse IV, Jan 23 2014
LINKS
F. Bertault, O. Ramaré, and P. Zimmermann, On sums of seven cubes, Math. Comp. 68 (1999), pp. 1303-1310.
Eric Weisstein's World of Mathematics, Waring's Problem.
FORMULA
A061439(n) + A181375(n) + A181377(n) + A181379(n) + A181381(n) + A181400(n) + a(n) + A181404(n) + A130130(n) = A002283(n).
Conjectured g.f.: x*(1+9*x+63*x^2+48*x^3)/(1-x). - Colin Barker, May 04 2012
Conjectured e.g.f.: 121*(exp(x) - 1) - 120*x - 111*x^2/2 - 8*x^3. - Stefano Spezia, May 21 2024
KEYWORD
nonn,more
AUTHOR
Martin Renner, Jan 28 2011
EXTENSIONS
a(5)-a(7) from Lars Blomberg, May 04 2011
a(8)-a(34) from Charles R Greathouse IV, Jan 23 2014
STATUS
approved