A044048 Catafusenes (see reference for precise definition).

1, 1, 3, 10, 37, 149, 630, 2713, 11899, 52789, 236345, 1066317, 4842531, 22117897, 101535659, 468233674, 2168094625, 10076216851, 46986691678, 219777820957, 1030892924479, 4848040645676, 22853639788127, 107970205586283

Offset

0,3

References

S. J. Cyvin et al., Enumeration and classification of certain polygonal systems...: annelated catafusenes, J. Chem. Inform. Comput. Sci., 34 (1994), 1174-1180.

Links

Table of n, a(n) for n=0..23.

Formula

G.f.: (6 - 18x^3 - (1-x)*(1-2x)*f(x) - 3*(1+2x)*f(x^2) - 2*f(x^3))/(12x^3), where f(x) = sqrt(1 - 6x + 5x^2) (follows from eq. (26) in Cyvin et al.).

Crossrefs

Sequence in context: A199874 A380651 A151058 * A192240 A231894 A086444

Adjacent sequences: A044045 A044046 A044047 * A044049 A044050 A044051

Keyword

nonn

Author

N. J. A. Sloane

Extensions

More terms from Emeric Deutsch, Mar 14 2004

Status

approved