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 A297207 #23 Feb 16 2025 08:33:52
%S A297207 13,85,104,175,308,351,490,680,832,1400,1625,2295,2464,2808,3179,3920,
%T A297207 4459,4725,5440,6656,8316,9295,9477,9724,10625,11200,13000,13230,
%U A297207 13475,17303,18360,19712,19760,21875,22464,25432,28561,29155,31360,35672,37800,38500,43520,43875
%N A297207 3d-congruent numbers: positive integers n for which there exists a trirectangular tetrahedron having volume n and rational areas and sides.
%C A297207 Ordered list of numbers A295507(i)*j^3 with i,j positive integers.
%H A297207 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TrirectangularTetrahedron.html">Trirectangular Tetrahedron</a>
%e A297207 a(1) = 13 = 13*1^3 = A295507(1)*A000578(1) is the volume of the trirectangular tetrahedron with sides: {240, 117, 44, 125, 244, 267}*1^3/15840.
%e A297207 a(3) = 104 = 13*2^3 = A295507(1)*A000578(2) is the volume of the trirectangular tetrahedron with sides: {240, 117, 44, 125, 244, 267}*2^3/15840.
%Y A297207 Cf. A295507, A000578 (cubes).
%K A297207 nonn
%O A297207 1,1
%A A297207 _Ralf Steiner_, Dec 27 2017