Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Directed and multi-directed animals on the king's lattice   This article introduces a new, simple solvable lattice for directed animals:
the directed king's lattice, or square lattice with next nearest neighbor bonds
and preferred directions {W, NW, N, NE, E}. We show that the directed animals
in this lattice have an algebraic generating function linked to the Schr\"oder
numbers and belong to the same universality class as the ones in the square and
triangular lattices. We also define multi-directed animals in the king's
lattice, which form a superclass of directed animals. We compute their
generating function and show that it is not D-finite. Finally, we propose
efficient random sampling algorithms for our animals.

22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
23
The categories of this paper are: solv-int
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex