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 A378207 #10 Feb 11 2025 09:56:10 %S A378207 5,8,9,2,5,5,6,5,0,9,8,8,7,8,9,6,0,3,6,6,7,3,7,0,3,0,1,7,5,4,0,4,0,8, %T A378207 6,6,0,7,0,6,9,6,6,1,4,7,4,0,3,9,5,0,3,0,4,9,0,2,8,3,2,2,4,1,6,2,8,0, %U A378207 5,1,9,9,3,5,9,2,1,1,2,6,6,1,8,7,6,6,1,4,7,2 %N A378207 Decimal expansion of the midradius of a triakis tetrahedron with unit shorter edge length. %C A378207 The triakis tetrahedron is the dual polyhedron of the truncated tetrahedron. %H A378207 <a href="/index/Al#algebraic_02">Index entries for algebraic numbers, degree 2</a>. %F A378207 Equals 5/(6*sqrt(2)) = 5/A010524. %e A378207 0.589255650988789603667370301754040866070696614740... %t A378207 First[RealDigits[5/Sqrt[72], 10, 100]] (* or *) %t A378207 First[RealDigits[PolyhedronData["TriakisTetrahedron", "Midradius"], 10, 100]] %o A378207 (PARI) 5/sqrt(72) \\ _Charles R Greathouse IV_, Feb 11 2025 %Y A378207 Cf. A378204 (surface area), A378205 (volume), A378206 (inradius), A378208 (dihedral angle). %Y A378207 Cf. A093577 (midradius of a truncated tetrahedron with unit edge). %Y A378207 Cf. A010524. %K A378207 nonn,cons,easy %O A378207 0,1 %A A378207 _Paolo Xausa_, Nov 21 2024