A002014 Number of symmetric filaments (strip polyominoes) with n square cells. (Formerly M0349 N0131)

1, 1, 1, 2, 2, 5, 5, 12, 12, 27, 28, 64, 67, 147, 158, 348, 373, 799, 879, 1886, 2069, 4335, 4864, 10204, 11432, 23488, 26814, 55179, 62925, 127133, 147414, 298212, 345415

Offset

0,4

References

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

R. C. Tilley, R. G. Stanton and D. D. Cowan, The cell growth problem for filaments, pp. 310-339 in Proceedings of the Louisiana Conference on Combinatorics, Graph Theory and Computer Science. Vol. 1, edited R. C. Mullin et al., 1970.

Links

Table of n, a(n) for n=0..32.

Crossrefs

Sequence in context: A325697 A184307 A032580 * A135153 A097896 A030223

Adjacent sequences: A002011 A002012 A002013 * A002015 A002016 A002017

Keyword

nonn

Author

N. J. A. Sloane

Extensions

a(23)-a(25) from Sean A. Irvine, May 21 2013

a(26)-a(32) from John Mason, Dec 05 2021

Status

approved