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 A085304 #13 Feb 16 2025 08:32:50
%S A085304 1,1,2,6,9,10,15,15,9,10,15,6,12,12
%N A085304 Least number of 4th powers required to represent n!.
%H A085304 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/BiquadraticNumber.html">Biquadratic Number</a>
%F A085304 "Shortest" solutions to n!=Sum[x(j)^4], j=1, .., m[n] with minimal value of m[n]: a(n)=Min{m[n]}. Per analogiam A084355.
%e A085304 n=6: 6!=720=625+81+14,length-of-solution=16>=a(6)
%e A085304 but 6!=720=2.256+13.16 seems shortest solution a(6)=15
%e A085304 after, see also A046046
%e A085304 n=7: 7!=5040=3.1296+4.256+8.16 so a(7)<=15 (uncertain);
%e A085304 n=8: a(8)<=9 because 8!=4.10000+1.256+4.16.
%Y A085304 Cf. A000142, A084355, A060387, A003336-A003346, A046046, A046044-A046050.
%K A085304 more,nonn
%O A085304 0,3
%A A085304 _Labos Elemer_, Jun 30 2003
%E A085304 a(7)-a(11) from _John W. Layman_, Aug 13 2004
%E A085304 a(12) from _Sean A. Irvine_, Feb 11 2010
%E A085304 a(13) from _Sean A. Irvine_, Feb 15 2010