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 A297305 #70 Jul 28 2025 08:59:06 %S A297305 5,10,15,20,25,30,31,35,40,45,50,55,60,62,65,70,75,80,85,89,90,93,95, %T A297305 100,103,105,110,115,120,124,125,130,135,140,145,150,155,160,165,170, %U A297305 175,178,180,185,186,190,195,200,205,206,210,215,217,220,225,230,233 %N A297305 Numbers k such that k^4 can be written as a sum of five positive 4th powers. %C A297305 If k is in the sequence, then k*m is in the sequence for every positive integer m. %H A297305 Jinyuan Wang, <a href="/A297305/b297305.txt">Table of n, a(n) for n = 1..500</a> %H A297305 Titus Piezas III, <a href="https://web.archive.org/web/20091022203521/http://www.geocities.com/titus_piezas/ramanujan_page10.html">Ramanujan and the Quartic Equation 2^4+2^4+3^4+4^4+4^4 = 5^4</a>, 2005. %H A297305 Jinyuan Wang, <a href="/A297305/a297305.txt">All solutions to k^4 = a^4 + b^4 + c^4 + d^4 + e^4 with k < 999</a>. %H A297305 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/DiophantineEquation4thPowers.html">Diophantine Equation 4th Powers</a>. %H A297305 <a href="/index/Di#Diophantine">Index to sequences related to Diophantine equations</a> (4,1,5) %e A297305 5^4 = 2^4 + 2^4 + 3^4 + 4^4 + 4^4 (= 625). %e A297305 31^4 = 10^4 + 10^4 + 10^4 + 17^4 + 30^4 (= 923521). %e A297305 89^4 = 10^4 + 35^4 + 52^4 + 60^4 + 80^4 (= 62742241). %e A297305 103^4 = 4^4 + 15^4 + 50^4 + 50^4 + 100^4 (= 112550881). %Y A297305 Cf. A000583, A003294, A023042, A301601, A386494. %K A297305 nonn %O A297305 1,1 %A A297305 _Seiichi Manyama_, Mar 16 2018 %E A297305 a(43)-a(57) from _Jon E. Schoenfield_, Mar 17 2018