2,3

Gill Barequet, Solomon W. Golomb, and David A. Klarner, Polyominoes. (This is a revision, by G. Barequet, of the chapter of the same title originally written by the late D. A. Klarner for the first edition, and revised by the late S. W. Golomb for the second edition.) Preprint, 2016, http://www.csun.edu/~ctoth/Handbook/chap14.pdf

G. Barequet, M. Shalah, Automatic Proofs for Formulae Enumerating Proper Polycubes, 31st International Symposium on Computational Geometry (SoCG'15). Editors: Lars Arge and János Pach; pp. 19-22, 2015.

R. Barequet, G. Barequet, and G. Rote, Formulae and growth rates of high-dimensional polycubes, Combinatorica, 30 (2010), 257-275. See Th. 6.

Vincenzo Librandi, Table of n, a(n) for n = 2..100

A. Asinowski, G. Barequet, R. Barequet, and G. Rote, Proper n-Cell Polycubes in n-3 Dimensions, J. Int. Seq. 15 (2012) #12.8.4.

M. Shalah, Formulae and growth rates of animals on cubical and triangular lattices, PhD Thesis, Israel Inst. Techn. (2017).

a(n) = 2^(n-3)*n^(n-5)*(n-2)*(2*n^2 - 6*n + 9).

Table[2^(n-3)n^(n-5)(n-2)(2n^2-6n+9), {n, 2, 30}] (* Harvey P. Dale, Nov 27 2024 *)

(Magma) [2^(n-3)*n^(n-5)*(n-2)*(2*n^2-6*n+9): n in [2..20]]; // Vincenzo Librandi, May 26 2011

Cf. A127670, A191092, A036364 (free).

Diagonal 2 of A195739.

Sequence in context: A294435 A361096 A137246 * A324449 A191589 A194729

Adjacent sequences: A171857 A171858 A171859 * A171861 A171862 A171863

N. J. A. Sloane, Oct 16 2010

Slightly edited by Gill Barequet, May 25 2011

approved