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A368387
a(n) is the denominator of the probability that the free polyomino with binary code A246521(n+1) appears in internal diffusion-limited aggregation on the square lattice.
9
1, 1, 3, 3, 35, 35, 35, 35, 35, 154, 462, 462, 231, 462, 231, 462, 924, 462, 462, 7, 924, 1846572, 492573081, 19019, 19019, 5073, 19019, 1804297, 7379372, 492573081, 7379372, 1804297, 19019, 1846572, 19019, 5534529, 7379372, 19019, 492573081, 5534529, 7379372, 19019, 19019, 7379372, 19019, 5534529, 19019, 19019, 14758744, 5534529, 7379372, 19019, 5534529, 44276232, 1844843, 19019
OFFSET
1,3
COMMENTS
In internal diffusion-limited aggregation on the square lattice, there is one initial cell in the origin. In each subsequent step, a new cell is added by starting a random walk at the origin, adding the first new cell visited. A368386(n)/a(n) is the probability that, when the appropriate number of cells have been added, those cells form the free polyomino with binary code A246521(n+1).
Can be read as an irregular triangle, whose n-th row contains A000105(n) terms, n >= 1.
LINKS
Pontus von Brömssen, Table of n, a(n) for n = 1..6473 (rows 1..10).
Persi Diaconis and William Fulton, A growth model, a game, an algebra, Lagrange inversion, and characteristic classes, Rend. Semin. Mat. Univ. Politec. Torino, Vol. 49 (1991), No. 1, 95-119.
Gregory F. Lawler, Maury Bramson, and David Griffeath, Internal diffusion limited aggregation, The Annals of Probability 20 no. 4 (1992), 2117-2140.
FORMULA
A368386(n)/a(n) = (A368392(n)/A368393(n))*A335573(n+1).
EXAMPLE
As an irregular triangle:
1;
1;
3, 3;
35, 35, 35, 35, 35;
154, 462, 462, 231, 462, 231, 462, 924, 462, 462, 7, 924;
...
There are only one monomino and one free domino, so both of these appear with probability 1, and a(1) = a(2) = 1.
For three squares, the probability for an L (or right) tromino (whose binary code is 7 = A246521(4)) is 2/3, so a(3) = 3. The probability for the straight tromino (whose binary code is 11 = A246521(5)) is 1/3, so a(4) = 3.
CROSSREFS
Cf. A000105, A246521, A335573, A367672, A367761, A367995, A368386 (numerators), A368389, A368391, A368392, A368393, A368660 (external diffusion-limited aggregation).
Sequence in context: A067098 A188897 A088060 * A213281 A303820 A206477
KEYWORD
nonn,frac,tabf
AUTHOR
STATUS
approved