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 A084863 #6 Feb 16 2025 08:32:49 %S A084863 0,0,0,0,1,0,0,0,0,0,1,0,0,1,0,0,0,0,0,1,1,0,0,0,0,0,0,0,1,1,0,0,0,0, %T A084863 2,0,0,0,0,0,0,0,0,1,1,0,0,0,0,1,0,0,1,0,0,1,0,0,1,0,0,1,0,0,0,1,0,0, %U A084863 0,0,0,0,0,0,1,0,2,0,0,1,0,0,1,1,0,0,0,0,0,0,0,0,1,0,0,0,0,1,1,0,1,0 %N A084863 Number of solutions to n = 2*u^2 + 3*v^2, u*v>0. %C A084863 a(A084864(n)) > 0. %H A084863 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/DiophantineEquation2ndPowers.html">Diophantine Equation: 2nd Powers.</a> %e A084863 n=770 = 2*19^2 + 3*4^2 = 2*17^2 + 3*8^2 = 2*13^2 + 3*12^2 = 2*1 + %e A084863 3*16^2, therefore a(770)=4. %Y A084863 Cf. A084865, A084866. %K A084863 nonn %O A084863 1,35 %A A084863 _Reinhard Zumkeller_, Jun 10 2003