

A038747


Coefficients arising in the enumeration of configurations of linear chains.


3



0, 0, 1, 4, 11, 32, 92, 254, 672, 1778, 4622, 11938, 30442, 77396, 194896, 489620, 1221134, 3040194, 7524933, 18600478, 45756483, 112444948, 275204606, 673031750
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OFFSET

1,4


COMMENTS

In the notation of Nemirovsky et al. (1992), a(n), the nth term of this sequence is p_{n,m}^{(l)} with m=1 and l=2. These numbers are given in Table II (p. 1093) in the paper. This sequence can be used for the calculation of sequence A033155(n) via Eq. (5) in the paper by Nemirovsky et al. (1992). (Note that, by equations (7b) in the paper, p_{n,1}^{(1)} = 0 for all n >= 1.)  Petros Hadjicostas, Jan 03 2019
In Table B1 (pp. 47384739), BennettWood et al. (1998) tabulated c_n(k)/4, for various values of n and k, where c_n(k) is "the number of SAWs of length n with k nearestneighbour contacts". (Here, the letter k stands for the letter m in the previous paragraph.) BennettWood et al. (1998) worked only with a square lattice (i.e., d=2) unlike Nemirovsky et al. (1992) who worked with a ddimensional hypercubic lattice. Both papers deal with SAWs = selfavoiding walks (in a lattice). We have c_n(k=1) = A033155(n) = 8*p_{n,1}^{(2)}, i.e., a(n) = p_{n,1}^{(2)} = (c_n(k=1)/4)/2, and this is the reason the numbers in Table B1 in BennettWood et al. (1998) must be divided by 2 in order to get extra terms for the current sequence (a(12) to a(24)).  Petros Hadjicostas, Jan 05 2019


LINKS

Table of n, a(n) for n=1..24.
D. BennettWood, I. G. Enting, D. S. Gaunt, A. J. Guttmann, J. L. Leask, A. L. Owczarek, and S. G. Whittington, Exact enumeration study of free energies of interacting polygons and walks in two dimensions, J. Phys. A: Math. Gen. 31 (1998), 47254741.
M. E. Fisher and B. J. Hiley, Configuration and free energy of a polymer molecule with solvent interaction, J. Chem. Phys., 34 (1961), 12531267.
A. M. Nemirovsky, K. F. Freed, T. Ishinabe, and J. F. Douglas, Marriage of exact enumeration and 1/d expansion methods: lattice model of dilute polymers, J. Statist. Phys., 67 (1992), 10831108; see Eq. 5 (p. 1090) and Eq. 7b (p. 1093).


CROSSREFS

Cf. A033155, A038749, A047057.
Sequence in context: A319918 A034754 A268744 * A052545 A183114 A183119
Adjacent sequences: A038744 A038745 A038746 * A038748 A038749 A038750


KEYWORD

nonn,more


AUTHOR

N. J. A. Sloane, May 02 2000


EXTENSIONS

The first two 0's in the sequence were inserted by Petros Hadjicostas, Jan 03 2019 to make it agree with Table II (p. 1093) and Eq. (5) (p. 1090) in the paper by Nemirovsky et al. (1992)
Terms a(12) to a(24) were copied from Table II, p. 4738, in the paper by BennettWood et al. (1998) (after division by 2) by Petros Hadjicostas, Jan 05 2019


STATUS

approved



