A121318 Molecular topological indices of the path graphs P_n

0, 4, 16, 38, 74, 128, 204, 306, 438, 604, 808, 1054, 1346, 1688, 2084, 2538, 3054, 3636, 4288, 5014, 5818, 6704, 7676, 8738, 9894, 11148, 12504, 13966, 15538, 17224, 19028, 20954, 23006, 25188, 27504, 29958, 32554, 35296, 38188, 41234, 44438

Offset

1,2

Comments

Maximum molecular topological index for alkane trees with n vertices.

See page 161 of Muller et al. paper for the definition of molecular topological index.

References

W. R. Muller, K. Szymanski, J.V. Knop and N. Trinajstich, "Molecular topological index", J. Chem. Inf. Comput. Sci., vol. 30 (1990),pp. 160-163. See Table 2 on page 162 column 4.

Links

Table of n, a(n) for n=1..41.

Eric Weisstein's World of Mathematics, Molecular Topological Index

Eric Weisstein's World of Mathematics, Path Graph

Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).

Formula

a(1) = 0; a(n) = (2n^3-3n^2+13n-18)/3 - Eric W. Weisstein, Jul 10 2011.

G.f.: 2*x^2*(x+1)*(2-2*x+x^2)/(1-x)^4. - Colin Barker, Aug 07 2012

Example

If n=10 then the maximum molecular topological index is 604 which is the tenth term in the sequence.

Crossrefs

Cf. A000602.

Sequence in context: A203299 A198015 A103770 * A152133 A371345 A297361

Adjacent sequences: A121315 A121316 A121317 * A121319 A121320 A121321

Keyword

nonn,easy

Author

Parthasarathy Nambi, Aug 25 2006

Status

approved