A393965 - OEIS

%I #9 Mar 09 2026 09:53:29

%S 8,5,5,5,9,9,6,7,7,1,6,7,3,5,2,1,9,2,9,6,9,2,3,5,7,6,6,2,1,1,1,7,6,3,

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

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

%N Decimal expansion of the height of an hexagonal antiprism with unit edges.

%H Paolo Xausa, <a href="/A393965/b393965.txt">Table of n, a(n) for n = 0..10000</a>

%H David I. McCooey, <a href="https://dmccooey.com/polyhedra/HexagonalAntiprism.html">Hexagonal Antiprism</a>.

%H Polytope Wiki, <a href="https://polytope.miraheze.org/wiki/Hexagonal_antiprism">Hexagonal antiprism</a>.

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

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Hexagonal_antiprism">Hexagonal antiprism</a>.

%F Equals sqrt(sqrt(3) - 1) = sqrt(A160390).

%F Equals the largest real root of x^4 + 2*x^2 - 2.

%e 0.85559967716735219296923576621117637584317804769...

%t First[RealDigits[Sqrt[Sqrt[3] - 1], 10, 100]]

%Y Cf. A385259 (surface area + 10), A393963 (volume), A019884 (midradius), A393964 (circumradius).

%Y Cf. A387296, A387297 (dihedral angles).

%Y Cf. A160390.

%K nonn,cons,easy

%O 0,1

%A _Paolo Xausa_, Mar 08 2026