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Number of planar partitions of n (A000219) that are non-squashing along rows and down columns (cf. A018819).
2

%I #8 Feb 28 2015 07:41:13

%S 1,1,3,4,9,13,25,33,56,76,122,170,264,360,538,707,1002,1332,1853,2409,

%T 3294

%N Number of planar partitions of n (A000219) that are non-squashing along rows and down columns (cf. A018819).

%H N. J. A. Sloane and J. A. Sellers, <a href="http://arXiv.org/abs/math.CO/0312418">On non-squashing partitions</a>, Discrete Math., 294 (2005), 259-274.

%e E.g. a(4) = 9:

%e 4.31.3.22.2.211.21..2..11

%e .....1....2.....1...1..11

%e ....................1....

%Y Cf. A000219, A000123, A018819, A008763, A001970, A089292.

%K nonn,more

%O 0,3

%A _N. J. A. Sloane_, Dec 25 2003

%E More terms from _Wouter Meeussen_, Dec 30 2003