OFFSET
2,1
COMMENTS
See the paper by Valentin Vankov Iliev for details.
LINKS
Valentin Vankov Iliev, A mathematical characterization of the groups of substitution isomerism of the linear alkanes, J. Math. Chem. 47 (2010), 52-61.
Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).
FORMULA
a(n) = (2 n^3 - 9 n^2 + 19 n - 14) where n is the number of carbons.
G.f.: 2*x^2*(2+3*x^2+x^3)/(x-1)^4. - R. J. Mathar, Apr 28 2009
EXAMPLE
The number of trisubstitution products with composition C_n H_(2n-1) X_2 Y for n = 10 is 1276.
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Parthasarathy Nambi, Apr 26 2009
EXTENSIONS
More terms from R. J. Mathar, Apr 28 2009
STATUS
approved