Acronym	oap, 8-ap
Name	octagonal antiprism
Circumradius	sqrt[(3-sqrt{2+sqrt(2)})/(8-4 sqrt{2+sqrt(2)})] = 1.375549
Vertex figure	[33,8]
General of army	(is itself convex)
Colonel of regiment	(is itself locally convex)
Dihedral angles	between {3} and {3}:   arccos([1-2 sqrt(2+sqrt(2))]/3) = 153.962383° between {3} and {8}:   arccos(-sqrt[(2-sqrt(2+sqrt(2)))/(6+3 sqrt(2+sqrt(2)))]) = 96.594518°
Face vector	16, 32, 18
Confer	more general: n-ap   general polytopal classes: segmentohedra
External links

Incidence matrix according to Dynkin symbol

s2s8s

demi( . . .  ) | 16 | 1 1  2 | 1  3
---------------+----+--------+-----
      s2s .    |  2 | 8 *  * | 0  2
      s . s2*a |  2 | * 8  * | 0  2
sefa( . s8s  ) |  2 | * * 16 | 1  1
---------------+----+--------+-----
      . s8s    ♦  8 | 0 0  8 | 2  *
sefa( s2s8s  ) |  3 | 1 1  1 | * 16

s2s16o

demi( . .  . ) | 16 |  2  2 | 1  3
---------------+----+-------+-----
      s2s  .   |  2 | 16  * | 0  2
sefa( . s16o ) |  2 |  * 16 | 1  1
---------------+----+-------+-----
      . s16o   ♦  8 |  0  8 | 2  *
sefa( s2s16o ) |  3 |  2  1 | * 16

xo8ox&#x   → height = sqrt[(1+sqrt(2+sqrt(2)))/(2+sqrt(2+sqrt(2)))] = 0.860296
({8} || dual {8})

o.8o.    | 8 * | 2  2 0 | 1 2 1 0
.o8.o    | * 8 | 0  2 2 | 0 1 2 1
---------+-----+--------+--------
x. ..    | 2 0 | 8  * * | 1 1 0 0
oo8oo&#x | 1 1 | * 16 * | 0 1 1 0
.. .x    | 0 2 | *  * 8 | 0 0 1 1
---------+-----+--------+--------
x.8o.    | 8 0 | 8  0 0 | 1 * * *
xo ..&#x | 2 1 | 1  2 0 | * 8 * *
.. ox&#x | 1 2 | 0  2 1 | * * 8 *
.o8.x    | 0 8 | 0  0 8 | * * * 1

snubbed forms: so8ox&#x