This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A135693 #26 Apr 26 2025 19:55:55
%S A135693 1,2,4,5,7,8,15,23,31,87,111,119,148,167,263,311,335,391,407,455,559,
%T A135693 599,839,951,1159,1231,1287,1303,1391,1455,1463,1607,1660,1679,1751,
%U A135693 1863,1991,2351,2615,2799,3247,3983,4327,4367,5199,5655,6047,6159,6351
%N A135693 Not the sum of three positive squares or cubes.
%C A135693 No other terms < 10^9. Presumably the sequence is finite.
%C A135693 Sum can include a mix of squares and cubes. - _James C. McMahon_, Apr 19 2025
%H A135693 Chai Wah Wu, <a href="/A135693/b135693.txt">Table of n, a(n) for n = 1..82</a>
%t A135693 lim=40000; s=Range[Sqrt[lim]]^2; c=Range[Surd[lim, 3]]^3; A135693=Complement[Range[lim], Select[Total/@Tuples[Union[s, c], {3}], #<=lim&]] (* _James C. McMahon_, Apr 19 2025 *)
%Y A135693 Cf. A113505, A135367.
%Y A135693 Cf. A004214, A057904.
%K A135693 nonn
%O A135693 1,2
%A A135693 _Zak Seidov_ and _Giovanni Resta_, Feb 24 2008
%E A135693 Edited by _N. J. A. Sloane_, Mar 01 2008