cp's OEIS Frontend

A181402 Total number of positive integers below 10^n requiring 7 positive cubes in their representation as sum of cubes.

%I A181402 #32 Feb 16 2025 08:33:13
%S A181402 1,10,73,121,121,121,121,121,121,121,121,121,121,121,121,121,121,121,
%T A181402 121,121,121,121,121,121,121,121,121,121,121,121,121,121,121,121
%N A181402 Total number of positive integers below 10^n requiring 7 positive cubes in their representation as sum of cubes.
%C A181402 An unpublished result of Deshouillers-Hennecart-Landreau, combined with Lemma 3 from Bertault, Ramaré, & Zimmermann implies that a(4)-a(34) are all 121.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
%H A181402 F. Bertault, O. Ramaré, and P. Zimmermann, <a href="https://doi.org/10.1090/S0025-5718-99-01071-6">On sums of seven cubes</a>, Math. Comp. 68 (1999), pp. 1303-1310.
%H A181402 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/WaringsProblem.html">Waring's Problem</a>.
%F A181402 A061439(n) + A181375(n) + A181377(n) + A181379(n) + A181381(n) + A181400(n) + a(n) + A181404(n) + A130130(n) = A002283(n).
%F A181402 Conjectured g.f.: x*(1+9*x+63*x^2+48*x^3)/(1-x). - _Colin Barker_, May 04 2012
%F A181402 Conjectured e.g.f.: 121*(exp(x) - 1) - 120*x - 111*x^2/2 - 8*x^3. - _Stefano Spezia_, May 21 2024
%Y A181402 Cf. A018890.
%Y A181402 Cf. A002283, A061439, A130130, A181375, A181377, A181379, A181381, A181400, A181404.
%K A181402 nonn,more
%O A181402 1,2
%A A181402 _Martin Renner_, Jan 28 2011
%E A181402 a(5)-a(7) from _Lars Blomberg_, May 04 2011
%E A181402 a(8)-a(34) from _Charles R Greathouse IV_, Jan 23 2014