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A181404
Total number of positive integers below 10^n requiring 8 positive cubes in their representation as sum of cubes.
10
0, 3, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15
OFFSET
1,2
COMMENTS
Also continued fraction expansion of (9+sqrt(229))/74. - Bruno Berselli, Sep 09 2011
FORMULA
A061439(n) + A181375(n) + A181377(n) + A181379(n) + A181381(n) + A181400(n) + A181402(n) + a(n) + A130130(n) = A002283(n).
a(n) = 15 for n > 2. - Charles R Greathouse IV, Sep 09 2011
G.f.: 3*x^2*(1+4*x)/(1-x). - Bruno Berselli, Sep 09 2011
E.g.f.: 3*(5*(exp(x) - 1 - x) - 2*x^2). - Stefano Spezia, May 21 2024
MATHEMATICA
PadRight[{0, 3}, 100, 15] (* Paolo Xausa, May 24 2024 *)
PROG
(PARI) a(n)=if(n>2, 15, 3*n-3) \\ Charles R Greathouse IV, Oct 07 2015
KEYWORD
nonn,easy
AUTHOR
Martin Renner, Jan 28 2011
EXTENSIONS
a(5)-a(7) from Lars Blomberg, May 04 2011
STATUS
approved