%I #10 Jan 03 2025 09:28:29

%S 2,6,7,9,9,6,9,3,4,0,2,0,4,8,3,5,5,7,8,5,7,9,5,5,3,3,2,7,4,5,9,8,0,6,

%T 7,6,7,0,8,5,4,2,3,0,3,8,1,6,8,2,7,7,3,3,2,1,5,2,6,8,9,0,3,6,3,3,7,1,

%U 5,1,7,6,3,8,1,7,0,2,0,9,1,9,7,1,5,0,0,0,0,6

%N Decimal expansion of the inradius of a disdyakis triacontahedron with unit shorter edge length.

%C The disdyakis triacontahedron is the dual polyhedron of the truncated icosidodecahedron (great rhombicosidodecahedron).

%H Paolo Xausa, <a href="/A379710/b379710.txt">Table of n, a(n) for n = 1..10000</a>

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/DisdyakisTriacontahedron.html">Disdyakis Triacontahedron</a>.

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Disdyakis_triacontahedron">Disdyakis triacontahedron</a>.

%F Equals sqrt(3477/964 + 7707/(964*sqrt(5))) = sqrt(3477/964 + 7707/(964*A002163)).

%e 2.679969340204835578579553327459806767085423038168...

%t First[RealDigits[Sqrt[3477/964 + 7707/(964*Sqrt[5])], 10, 100]] (* or *)

%t First[RealDigits[PolyhedronData["DisdyakisTriacontahedron", "Inradius"], 10, 100]]

%Y Cf. A379708 (surface area), A379709 (volume), A379388 (midradius), A379711 (dihedral angle).

%Y Cf. A002163.

%K nonn,cons,easy

%O 1,1

%A _Paolo Xausa_, Dec 31 2024