A371397 - OEIS

%I #14 Sep 20 2024 06:06:53

%S 0,0,0,1,6,54,416,3111,22898,168460,1242985,9227333,68949103,

%T 518618196,3925228596,29879207817,228630283775,1757699977107,

%U 13570824097968,105182547181534,818093724437992,6383353614308209

%N Number of chiral pairs of polyominoes with n cubical cells of the regular tiling with Schläfli symbol {4,3,4}.

%C Also called polycubes. Each member of a chiral pair is a reflection but not a rotation of the other.

%F a(n) = A000162(n) - A038119(n) = (A000162(n) - A007743(n))/2 = A038119(n) - A007743(n).

%e Polyominoes with cell centers at (0,0,0), (0,0,1), (0,1,1), (1,1,1) and (0,0,0), (0,1,0), (0,1,1), (1,1,1) are a chiral pair.

%Y Cf. A000162 (oriented), A038119 (unoriented), A007743 (achiral), A001931 (fixed).

%K nonn,more

%O 1,5

%A _Robert A. Russell_, Mar 21 2024

%E a(17)-a(22) from _John Mason_, Sep 19 2024