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 A027709 Minimal perimeter of polyomino with n square cells. 13
 0, 4, 6, 8, 8, 10, 10, 12, 12, 12, 14, 14, 14, 16, 16, 16, 16, 18, 18, 18, 18, 20, 20, 20, 20, 20, 22, 22, 22, 22, 22, 24, 24, 24, 24, 24, 24, 26, 26, 26, 26, 26, 26, 28, 28, 28, 28, 28, 28, 28, 30, 30, 30, 30, 30, 30, 30, 32, 32, 32, 32, 32, 32, 32, 32, 34, 34, 34, 34, 34, 34 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 REFERENCES F. Harary and H. Harborth, Extremal Animals, Journal of Combinatorics, Information & System Sciences, Vol. 1, No 1, 1-8 (1976). W. C. Yang, Optimal polyform domain decomposition (PhD Dissertation), Computer Sciences Department, University of Wisconsin-Madison, 2003. LINKS Reinhard Zumkeller, Table of n, a(n) for n = 0..10000 Henri Picciotto, Geometry Labs, Labs 8.1-8.3. J. Yackel, R. R. Meyer and I. Christou, Minimum-perimeter domain assignment, Mathematical Programming, vol. 78 (1997), pp. 283-303. Jason R. Zimba, Solution to Perimeter Problem, Jan 23 2015 FORMULA a(n) = 2*ceiling(2*sqrt(n)). a(n) = 2*A027434(n) for n > 0. - Tanya Khovanova, Mar 04 2008 EXAMPLE a(5) = 10 because we can arrange 5 squares into 2 rows, with 2 squares in the top row and 3 squares in the bottom row. This shape has perimeter 10, which is minimal for 5 squares. MAPLE interface(quiet=true); for n from 0 to 100 do printf("%d, ", 2*ceil(2*sqrt(n))) od; MATHEMATICA Table[2*Ceiling[2*Sqrt[n]], {n, 0, 100}] (* Wesley Ivan Hurt, Mar 01 2014 *) PROG (Haskell) a027709 0 = 0 a027709 n = a027434 n * 2  -- Reinhard Zumkeller, Mar 23 2013 (MAGMA) [2*Ceiling(2*Sqrt(n)): n in [0..100]]; // Vincenzo Librandi, May 11 2015 CROSSREFS Cf. A000105, A067628 (analog for triangles), A075777 (analog for cubes). Cf. A135711. Number of such polyominoes is in A100092. Sequence in context: A163639 A196355 A095253 * A196358 A079775 A247654 Adjacent sequences:  A027706 A027707 A027708 * A027710 A027711 A027712 KEYWORD easy,nonn AUTHOR Jonathan Custance (jevc(AT)atml.co.uk) EXTENSIONS Edited by Winston C. Yang (winston(AT)cs.wisc.edu), Feb 02 2002 STATUS approved

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Last modified December 14 14:20 EST 2019. Contains 329979 sequences. (Running on oeis4.)