A220836 Triangle read by rows giving coefficients of Zhang-Zhang polynomial for benzenoidal system S(n).

1, 1, 2, 1, 4, 4, 1, 6, 13, 9, 1, 8, 26, 38, 20, 1, 10, 43, 96, 106, 45, 1, 12, 64, 190, 321, 284, 101, 1, 14, 89, 328, 742, 1006, 742, 227, 1, 16, 118, 518, 1460, 2660, 3006, 1900, 510

Offset

1,3

Links

Table of n, a(n) for n=1..45.

C.-P. Chou and H. A. Witek, An Algorithm and FORTRAN Program for Automatic Computation of the Zhang-Zhang Polynomial of Benzenoids, MATCH: Commun. Math. Comput. Chem, 68 (2012) 3-30.

Formula

Chou and Witek give a g.f.

Example

Triangle begins:
1
1 2
1 4 4
1 6 13 9
1 8 26 38 20
1 10 43 96 106 45
1 12 64 190 321 284 101
1 14 89 328 742 1006 742 227
1 16 118 518 1460 2660 3006 1900 510
...

Crossrefs

Right hand diagonal is A052534.

Sequence in context: A303872 A013609 A154558 * A008572 A209150 A209145

Adjacent sequences: A220833 A220834 A220835 * A220837 A220838 A220839

Keyword

nonn,tabl

Author

N. J. A. Sloane, Dec 23 2012

Status

approved