1,2

The three possible assumptions considered here are the following:

s (for n odd) indicates that we are working in the "supergroup" and so take account of twists of the face centers.

m (for n > 3) indicates that the pieces are marked so that we take account of the permutation of the identically-colored pieces on a face.

i (for n > 3) indicates that we are working in the theoretical invisible group and solve the pieces on the interior of the cube as well as the exterior. It is assumed that the M and S traits apply to the interior pieces as if they were on the exterior of a smaller cube.

Dan Hoey, posting to Cube Lovers List, Jun 24, 1987.

C. A. Pickover, The Math Book, Sterling, NY, 2009; see p. 452.

Alan Bawden, Cube Lovers Archive, Part 6

f := proc(n) local A, B, C, D, E, F, G; if n mod 2 = 1 then A := (n-1)/2; B := (n-1)/2; C := (n-1)/2; D := 0; E := (n+4)*(n-1)*(n-3)/24; F := 0; G := 0; else A := n/2; B := n/2; C := 0; D := 0; E := n*(n^2-4)/24; F := 1; G := 0; fi; (2^A*((8!/2)*3^7)^B*((12!/2)*2^11)^C*((4^6)/2)^D*(24!/2)^E)/(24^F*((24^6)/2)^G); end;

See A007458, A054434, A075152, A080656-A080662 for other versions.

Sequence in context: A075152 A080658 A080656 this_sequence A080661 A080662 A080660

Adjacent sequences: A074911 A074912 A074913 this_sequence A074915 A074916 A074917

nonn

N. J. A. Sloane (njas(AT)research.att.com), Feb 28 2003