|
%I #55 Aug 09 2018 05:21:27
%S 1,24,1560,119580,10166403,915103765,85747377755,8274075616387,
%T 816630819554486,82052796578652749
%N Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 2 X 4.
%C a(6) is often quoted as 102981500, but this is incorrect.
%D Anthony Lane, The Joy of Bricks, The New Yorker, Apr 27-May 04, 1998, pp. 96-103.
%H M. Abrahamsen and S. Eilers, <a href="http://dx.doi.org/10.1080/10586458.2011.564539">On the asymptotic enumeration of LEGO structures</a>, Exper. Math. 20 (2) (2011) 145-152.
%H B. Durhuus and S. Eilers, <a href="http://arxiv.org/abs/math/0504039">On the entropy of LEGO</a>, arXiv:math/0504039 [math.CO], 2005.
%H B. Durhuus and S. Eilers, <a href="http://dx.doi.org/10.1007/s12190-013-0730-9">On the entropy of LEGO</a>, J. Appl. Math. Comput. 45 (1-2) (2014), 433-448.
%H S. Eilers, <a href="http://www.jstor.org/stable/10.4169/amer.math.monthly.123.5.415">The LEGO counting problem</a>, Amer. Math. Monthly, 123 (May 2016), 415-426.
%H S. Eilers and M. Abrahamsen, <a href="http://www.math.ku.dk/~eilers/papers/eclbii.pdf">Efficient counting of LEGO structures</a>, March 30 2007.
%H <a href="/wiki/Index_to_OEIS:_Section_Lc#LEGO">Index entry for sequences related to LEGO blocks</a>
%Y Cf. A112390, A272690.
%K nonn,hard,more
%O 1,2
%A _N. J. A. Sloane_, Dec 06 2005
%E Thanks to _Gerald McGarvey_, _Christian Schroeder_ and _Jud McCranie_ who contributed to this entry.
%E a(8) from _Søren Eilers_, Oct 29 2006
%E a(9) from _Johan Nilsson_, Jan 06 2014
%E a(10) from _Matthias Simon_, Apr 06 2018
| 