A047754 Number of dissectable polyhedra with n tetrahedral cells and symmetry of type H.

0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 5, 0, 0, 0, 26, 0, 0, 0, 133, 0, 0, 0, 708, 0, 0, 0, 3861, 0, 0, 0, 21604, 0, 0, 0, 123266, 0, 0, 0, 715221, 0, 0, 0, 4206956, 0, 0, 0, 25032840, 0, 0, 0, 150413348, 0, 0, 0, 911379384, 0, 0, 0, 5562367173, 0, 0, 0, 34164355848

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn

Comments

One of 17 different symmetry types comprising A007173 and A027610 and one of 10 for A371351. Also the number of tetrahedral clusters or polyominoes of the regular tiling with Schläfli symbol {3,3,oo}, both having type H achiral symmetry and n tetrahedral cells. The axis of symmetry is the line joining the centers of opposite edges of a tetrahedral cell (31); the order of the symmetry group is 4. An achiral polyomino is identical to its reflection. - Robert A. Russell, Mar 22 2024

Links

• L. W. Beineke and R. E. Pippert, Enumerating dissectable polyhedra by their automorphism groups, Canad. J. Math., 26 (1974), 50-67.
• Robert A. Russell, Mathematica Graphics3D program for A047754 example

Crossrefs

Cf. A047755.

Cf. A007173 (oriented), A027610 (unoriented), A371351 (achiral), A001764 (rooted), A047751 (type K), A047753 (type I).

Programs

Mathematica

Table[If[1==Mod[n,4],Binomial[(3n-3)/4,(n-1)/4]/(n+1)-If[1==Mod[n,8],2Binomial[(3n-3)/8,(n-1)/8],4Binomial[(3n-7)/8,(n-5)/8]]/(n+3),0],{n,40}] (* Robert A. Russell, Mar 22 2024 *)

Formula

If n=4m+1 then (1/2)*(A001764(m) - A047753(n) - A047751(n)), otherwise 0.

G.f.: z * (G(z^4) - G(z^8) - z^4*G(z^8)^2) / 2, where G(z) = 1 + z*G(z)^3 is the g.f. for A001764. - Robert A. Russell, Mar 22 2024