OFFSET
0,2
REFERENCES
Per Hakan Lundow, "Computation of matching polynomials and the number of 1-factors in polygraphs", Research report, No 12, 1996, Department of Math., Umea University, Sweden.
LINKS
Sergey Perepechko, Table of n, a(n) for n = 0..300
A. M. Karavaev, S. N. Perepechko, Dimer problem on cylinders: recurrences and generating functions, (in Russian), Matematicheskoe Modelirovanie, 2014, V.26, No.11, pp.18-22.
Per Hakan Lundow, Enumeration of matchings in polygraphs, 1998.
Sergey Perepechko, Generating function for A028484
FORMULA
G.f.: see links.
a(n) = 2^n * sqrt(Resultant(U_{2*n}(x/2), T_{13}(i*x/2))), where T_n(x) is a Chebyshev polynomial of the first kind, U_n(x) is a Chebyshev polynomial of the second kind and i = sqrt(-1). - Seiichi Manyama, Apr 17 2020
PROG
(PARI) {a(n) = sqrtint(4^n*polresultant(polchebyshev(2*n, 2, x/2), polchebyshev(13, 1, I*x/2)))} \\ Seiichi Manyama, Apr 17 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
a(10)-a(11) from Alois P. Heinz, Dec 10 2013
STATUS
approved