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 A047801 #22 Sep 27 2023 09:13:22
%S A047801 1,5,14,29,50,74,111,149,197,247,308,370,451,526,613,706,815,914,1037,
%T A047801 1146,1284,1416,1565,1698,1876,2030,2209,2380,2578,2757,2972,3168,
%U A047801 3401,3612,3850,4071,4339,4575,4843,5089,5388
%N A047801 Number of different values of i^2+j^2+k^2+l^2 for i,j,k,l in [ 0,n ].
%H A047801 Robin Visser, <a href="/A047801/b047801.txt">Table of n, a(n) for n = 0..5000</a> (terms n = 0..100 from T. D. Noe).
%t A047801 Table[ Length@Union@Flatten@Table[ i^2+j^2+k^2+l^2, {i, 0, n}, {j, i, n}, {k, j, n}, {l, k, n} ], {n, 0, 48} ]
%Y A047801 Cf. A034966, A047800.
%Y A047801 Partial sums of A122927.
%K A047801 nonn,easy,nice
%O A047801 0,2
%A A047801 _Wouter Meeussen_
%E A047801 Definition corrected by _Jonathan Vos Post_, Nov 14 2007