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 A186685 #25 Feb 16 2025 08:33:14
%S A186685 0,1,6,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
%T A186685 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
%U A186685 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
%N A186685 Total number of n-digit numbers requiring 19 positive biquadrates in their representation as sum of biquadrates.
%H A186685 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/WaringsProblem.html">Waring's Problem.</a>
%H A186685 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (1).
%F A186685 a(n) = A186684(n) - A186684(n-1).
%F A186685 A161905(n) + A186650(n) + A186652(n) + A186654(n) + A186656(n) + A186658(n) + A186660(n) + A186662(n) + A186664(n) + A186666(n) + A186668(n) + A186670(n) + A186672(n) + A186674(n) + A186676(n) + A186678(n) + A186681(n) + A186683(n) + a(n) = A052268(n).
%F A186685 a(n) = 0 for n >= 4. - _Nathaniel Johnston_, May 09 2011
%t A186685 PadRight[{0, 1, 6}, 100] (* _Paolo Xausa_, Jul 26 2024 *)
%Y A186685 Cf. A046050, A052268, A099591.
%Y A186685 Cf. A161905, A186650, A186652, A186654, A186656, A186658, A186660(n) + A186662, A186664, A186666, A186668, A186670, A186672, A186674, A186676, A186678, A186681, A186683, A186684.
%K A186685 nonn,base,easy
%O A186685 1,3
%A A186685 _Martin Renner_, Feb 25 2011